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"text": "# Build a latency-efficient PyTorch two-tower neural-network ranker\n\nBuild a two-tower neural network in CPU PyTorch for the \"Made for You\" shelf of\na music streaming service. Although the supplied benchmark is small, it\nrepresents a production system with millions of users and millions of items;\nthe training approach must scale to that setting and therefore must not\nconstruct or decompose a global user-item interaction matrix. The production\nshelf has a strict request-time latency budget. Candidate item embeddings are\ncomputed offline and stored in a nearest-neighbor index. At request time, the\nsystem computes one user embedding and retrieves items by maximum inner-product\nsearch.\n\nThe model must therefore decompose exactly into a user vector and an\nindependently precomputable item vector of the same dimensionality, with the\nfinal relevance score equal to their dot product. Both vectors must be produced\nby separate trainable user and item towers implemented as PyTorch neural\nnetworks. The user tower must derive its representation from interaction\nhistory rather than a user-ID lookup. Per-user candidate eligibility,\ncutoff-specific explicit preference state, and a temporal backtest are\nprovided. Candidate eligibility is platform-owned; all modeling within that\ncandidate boundary is in scope.\n\n## Data\n\nAll inputs are under `/task/data/`. Training data ends at timestamp `24786800`.\nA 30-minute gap precedes a seven-day public validation window. The hidden test\nis the following seven-day window after another 30-minute gap.\n\nFor each event family there is a `train_*.parquet` and `val_*.parquet` file:\n\n| Family | Meaning | Columns |\n| --- | --- | --- |\n| `listens` | Playback events | `uid`, `timestamp`, `item_id`, `is_organic`, `played_ratio_pct`, `track_length_seconds` |\n| `likes` | Explicit positive actions | `uid`, `timestamp`, `item_id`, `is_organic` |\n| `dislikes` | Explicit negative actions | `uid`, `timestamp`, `item_id`, `is_organic` |\n| `unlikes` | Reversal of a prior like | `uid`, `timestamp`, `item_id`, `is_organic` |\n| `undislikes` | Reversal of a prior dislike | `uid`, `timestamp`, `item_id`, `is_organic` |\n\n`is_organic=1` means the listener sought out the track; `0` means the action\ncame through a recommendation surface. A listen is a conventional positive at\n50% completion. The discovery-quality objective below uses the stronger 80%\nthreshold.\n\nThe two public windows have different roles:\n\n1. Build and tune a validation ranker using only `train_*` as history and\n `val_*` as subsequent outcomes.\n2. After selecting the approach, refit it on `train_* + val_*`. At hidden-test\n time the validation events are observed history, not recommendable outcomes.\n\nDo not use `val_*` events as features when measuring a validation ranking. They\nmay and should be used when refitting the final hidden-test ranker.\n\nAdditional files under `/task/data/`:\n\n- `candidate_catalog.parquet`: the 30,000 retrieval-catalog tracks, ordered by\n training positive-listen popularity.\n- `target_users.parquet`: users with at least 20 positive listens in the 90 days\n before the training cutoff, selected without future labels.\n- `validation_preference_state.parquet`: active explicit state at the training\n cutoff, for validation ranking.\n- `test_preference_state.parquet`: active explicit state after validation, for\n the final hidden-test ranking. State is `liked` or `disliked`; a pair may have\n both active channels.\n- `validation_eligible_candidates.npz` and `test_eligible_candidates.npz`:\n cutoff-correct candidate sets for every target user. Each contains aligned\n arrays `uids`, `item_ids`, and `packed_eligible`. For user row `r`, recover\n the Boolean item mask with `np.unpackbits(packed_eligible[r],\n count=len(item_ids), bitorder=\"little\")`.\n\nThe exact available Python distribution inventory is listed in\n`/task/requirements.txt`. Future test interactions are hidden and used only by\nthe separate Harbor verifier.\n\n## Discovery objective\n\nRank only the candidates returned for the relevant cutoff. Relevance is based\non organic behavior in the immediately following window:\n\n- grade 3: the user organically likes the track;\n- grade 1: the user organically listens to at least 80% of the track;\n- grade 0: otherwise.\n\nIf both positive events occur, grade 3 wins. Ranking quality is measured with\ngraded NDCG@10. DCG uses gain `2^grade - 1` and discount\n`1/log2(rank + 1)`, then averages per-user NDCG over users with at least one\nrelevant item.\n\nThe public evaluator reports this objective for development, but its score is\nnot a separate acceptance stage. Final acceptance is determined on the hidden\ntest using the same objective.\n\nThe Yambda logs contain interactions, not impression propensities. Treat the\norganic objective as a robust offline target, not as a causal estimate of\nonline lift.\n\n## Public tools\n\n`/task/evaluate_public.py` scores a validation-stage ranking against the public\nwindow. Pass the path to a ranking with the same schema as the final\ndeliverable:\n\n```sh\npython /task/evaluate_public.py solution/validation.parquet\n```\n\nStage-independent evaluation helpers are available in\n`/task/ranking_evaluation.py`. The builder installs the same checked-in module\nin the public agent image and private verifier image so scoring mechanics cannot\ndrift. The public copy contains no hidden labels, evaluator-owned data paths, or\npass thresholds.\n\nThe public evaluator uses `validation_eligible_candidates.npz`; it is not a\nvalidator for the final artifact. No model implementation, fitted\nrepresentation, or example submission is supplied. Design and tune the\nrequired PyTorch neural two-tower model, then refit the selected approach as\ndescribed above.\n\n## Deliverable\n\nWrite `/app/solution/submission.parquet` or\n`/app/solution/submission.csv`, with exactly 100 rows for every target user and\ncolumns `uid`, `item_id`, `rank`. Ranks must be the integers 1-100 with no ties\nor duplicate items. Every submitted item must be present in that user's\n`test_eligible_candidates.npz` candidate set.\n\nLeave the code that defines, trains, and applies both towers, along with a\nconcise `/app/solution/README.md`, in `/app/solution/`. The README should state\nthe model architecture, training objective, public validation score, and final\nsubmission command. Keep the best valid submission saved throughout the\nattempt so it survives the deadline.\n\n## Constraints\n\n- Write deliverables and intermediate artifacts only under `/app/solution/`.\n- Treat `/task/` and the installed Python environment as read-only.\n- Do not invoke nested agents or attempt to access verifier files, credentials,\n other trials, or host paths.\n- Do not install packages or use network access except for the model provider\n connection managed by Harbor.\n- The environment includes CPU PyTorch 2.8.0. No accelerator is available.\n- You have up to 60 minutes. Improve the model as much as possible within that\n limit. Structural validity alone is not sufficient; the final submission is\n also evaluated for ranking quality.\n"
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"content": "- dataviz: Use this skill whenever you are about to create ANY chart, graph, plot, dashboard, or data visualization, in ANY output medium — an HTML or React artifact, inline SVG, plotting code in any library (matplotlib, plotly, d3, Recharts, …), an image/PNG you will render and upload, or a chart shared into Slack. Read it BEFORE writing the first line of chart code, choosing chart colors, building a stat tile / meter / KPI row, or laying out a dashboard. When the destination is a first-party document connector (host-designated, never self-described) that renders live charts, hand it the rows (inline, or as an uploaded data file the chart cites) rather than a rendered PNG/SVG — a picture of a chart loses hover, data inspection and per-value comments. Produces visualizations that read as one system — elegant, accessible, consistent in light and dark — using a brand-neutral placeholder palette you swap for your own. Teaches a design-system-agnostic method: a form heuristic, a color formula with a runnable validator, mark specs, and interaction rules. A validated default palette is documented in `references/palette.md` — swap that file's values for your brand's. Triggers on: \"chart\", \"graph\", \"plot\", \"data viz\", \"visualization\", \"dashboard\", \"analytics\", \"visualize data\", \"categorical colors\", \"sequential / diverging palette\", \"stat tile\", \"sparkline\", \"heatmap\", \"legend\", \"axis\", \"tooltip\", \"chart colors\", \"color by series\".\n- update-config: Use this skill to configure the Claude Code harness via settings.json. Automated behaviors (\"from now on when X\", \"each time X\", \"whenever X\", \"before/after X\") require hooks configured in settings.json - the harness executes these, not Claude, so memory/preferences cannot fulfill them. Also use for: permissions (\"allow X\", \"add permission\", \"move permission to\"), env vars (\"set X=Y\"), hook troubleshooting, or any changes to settings.json/settings.local.json files. Examples: \"allow npm commands\", \"add bq permission to global settings\", \"move permission to user settings\", \"set DEBUG=true\", \"when claude stops show X\". For simple settings like theme/model, suggest the /config command.\n- keybindings-help: Use when the user wants to customize keyboard shortcuts, rebind keys, add chord bindings, or modify ~/.claude/keybindings.json. Examples: \"rebind ctrl+s\", \"add a chord shortcut\", \"change the submit key\", \"customize keybindings\".\n- code-review: Review the current diff, or a PR number/branch/path target, for correctness bugs and reuse/simplification/efficiency cleanups at the given effort level (low/medium: fewer, high-confidence findings; high→max: broader coverage, may include uncertain findings); with no level given, it reuses the level you typed last. Pass --comment to post findings as inline PR comments, or --fix to apply the findings to the working tree after the review.\n- simplify: Review the changed code for reuse, simplification, efficiency, and altitude cleanups, then apply the fixes. Quality only — it does not hunt for bugs; use /code-review for that.\n- fewer-permission-prompts: Scan your transcripts for common read-only Bash and MCP tool calls, then add a prioritized allowlist to project .claude/settings.json to reduce permission prompts.\n- loop: Run a prompt or slash command on a recurring interval (e.g. /loop 5m /foo). Omit the interval to let the model self-pace. - When the user wants to set up a recurring task, poll for status, or run something repeatedly on an interval (e.g. \"check the deploy every 5 minutes\", \"keep running /babysit-prs\"). Do NOT invoke for one-off tasks.\n- schedule: Create, update, list, or run scheduled cloud agents (routines) that execute on a cron schedule. - When the user wants to schedule a recurring cloud agent, set up automated tasks, create a cron job for Claude Code, or manage their scheduled agents/routines. Also use when the user wants a one-time scheduled run (\"run this once at 3pm\", \"remind me to check X tomorrow\").\n- claude-api: Reference for the Claude API / Anthropic SDK — model ids, pricing, params, streaming, tool use, MCP, agents, caching, token counting, model migration.\nTRIGGER — read BEFORE opening the target file; don't skip because it \"looks like a one-liner\" — whenever: the prompt names Claude/Anthropic in any form (Claude, Anthropic, Fable, Opus, Sonnet, Haiku, `anthropic`, `@anthropic-ai`, `claude-*`, `us.anthropic.*`, `[1m]`); the user asks about an LLM (pricing/model choice/limits/caching) — never answer from memory; OR the task is LLM-shaped with provider unstated (agent/MCP/tool-definition/multi-agent/RAG/LLM-judge/computer-use; generate/summarize/extract/classify/rewrite/converse over NL; debugging refusals/cutoffs/streaming/tool-calls/tokens).\nSKIP only when another provider is being worked on (overrides all triggers): OpenAI/GPT/Gemini/Llama/Mistral/Cohere/Ollama named in the query; OR `grep -rE 'openai|langchain_openai|google.generativeai|genai|mistralai|cohere|ollama'` over the project hits (run this grep FIRST if no provider named — don't Read the file).\n- workflow-authoring: Reference for writing a Workflow tool script (script API and gotchas, resume, quality patterns, worked examples). Load before authoring a script for a workflow the user already opted into; it does not itself authorize running one.\n- run: Launch and drive this project's app to see a change working. Use when asked to run, start, or screenshot the app, or to confirm a change works in the real app (not just tests). First looks for a project skill that already covers launching the app; otherwise falls back to built-in patterns per project type (CLI, server, TUI, Electron, browser-driven, library).\n- init: Initialize a new CLAUDE.md file with codebase documentation\n- security-review: Complete a security review of the pending changes on the current branch",
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"text": "I'll start by exploring the data and environment."
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"command": "ls -la /task/ /task/data/ && cat /task/requirements.txt | head -50",
"description": "List task files"
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"timestamp": "2026-08-29T02:33:21.210Z",
"content": "/task/:\ntotal 36\ndr-xr-xr-x 1 root root 4096 Aug 29 02:29 .\ndrwxr-xr-x 1 root root 4096 Aug 29 02:31 ..\n-r--r--r-- 1 root root 0 Aug 29 02:15 .keep\ndr-xr-xr-x 1 root root 4096 Aug 29 02:15 data\n-r--r--r-- 1 root root 5774 Aug 29 02:15 evaluate_public.py\n-r--r--r-- 1 root root 8265 Aug 29 02:15 ranking_evaluation.py\n-r--r--r-- 1 root root 1295 Aug 29 02:15 requirements.txt\n\n/task/data/:\ntotal 347392\ndr-xr-xr-x 1 root root 4096 Aug 29 02:15 .\ndr-xr-xr-x 1 root root 4096 Aug 29 02:29 ..\n-r--r--r-- 1 root root 349352 Aug 29 02:15 candidate_catalog.parquet\n-r--r--r-- 1 root root 84127 Aug 29 02:15 target_users.parquet\n-r--r--r-- 1 root root 7736341 Aug 29 02:15 test_eligible_candidates.npz\n-r--r--r-- 1 root root 1092329 Aug 29 02:15 test_preference_state.parquet\n-r--r--r-- 1 root root 857213 Aug 29 02:15 train_dislikes.parquet\n-r--r--r-- 1 root root 5374652 Aug 29 02:15 train_likes.parquet\n-r--r--r-- 1 root root 319183255 Aug 29 02:15 train_listens.parquet\n-r--r--r-- 1 root root 155988 Aug 29 02:15 train_undislikes.parquet\n-r--r--r-- 1 root root 1855885 Aug 29 02:15 train_unlikes.parquet\n-r--r--r-- 1 root root 36571 Aug 29 02:15 val_dislikes.parquet\n-r--r--r-- 1 root root 298484 Aug 29 02:15 val_likes.parquet\n-r--r--r-- 1 root root 9947609 Aug 29 02:15 val_listens.parquet\n-r--r--r-- 1 root root 7845 Aug 29 02:15 val_undislikes.parquet\n-r--r--r-- 1 root root 72536 Aug 29 02:15 val_unlikes.parquet\n-r--r--r-- 1 root root 7573821 Aug 29 02:15 validation_eligible_candidates.npz\n-r--r--r-- 1 root root 1061761 Aug 29 02:15 validation_preference_state.parquet\n# Exact distribution inventory for the Yambda two-tower task family.\n#\n# This is an input to `uv pip sync`, not a list of minimum requirements. A\n# conforming task environment contains exactly these third-party Python\n# distributions and no others. Python itself is pinned by task.toml and both\n# Harbor image Dockerfiles.\nattrs==26.1.0\nbleach==6.4.0\ncertifi==2026.7.22\nchardet==7.6.0\ncharset-normalizer==3.5.1\nfastjsonschema==2.22.2\nfilelock==3.32.3\nfsspec==2026.7.0\nidna==3.18\nJinja2==3.1.6\njoblib==1.5.3\njsonschema==4.26.0\njsonschema-specifications==2025.9.1\njupyter-core==5.9.1\njupytext==1.19.5\nkaggle==2.2.4\nkagglesdk==0.1.37\nmarkdown-it-py==4.2.0\nMarkupSafe==3.0.3\nmdit-py-plugins==0.6.1\nmdurl==0.1.2\nmpmath==1.3.0\nnbformat==5.11.1\nnetworkx==3.6.1\nnumpy==2.2.6\npackaging==26.3\npandas==2.3.3\npillow==12.3.0\npip==26.0.1\nplatformdirs==4.11.3\nprotobuf==7.35.1\npyarrow==18.1.0\npython-dateutil==2.9.0.post0\npython-dotenv==1.2.3\npython-slugify==8.0.4\npytz==2026.3.post1\nPyYAML==6.0.3\nreferencing==0.37.0\nreportlab==4.2.5\nrequests==2.34.2\nrpds-py==2026.6.3\nscikit-learn==1.7.2\nscipy==1.15.3\nsetuptools==84.0.0",
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"command": "cat /task/ranking_evaluation.py; echo \"=====EVAL=====\"; cat /task/evaluate_public.py",
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"timestamp": "2026-08-29T02:33:21.717Z",
"content": "\"\"\"Shared public primitives for Yambda discovery-ranking evaluation.\n\nBoth the solver-visible validation evaluator and the private submission judge\nimport this module from the generated task's ``public`` directory. It owns the\nstage-independent contract: reading a ranking, validating its shape, converting\nit to per-user rank order, looking up packed candidate eligibility, and\ncomputing graded NDCG@10.\n\nThe module deliberately contains no event-derived labels, private artifact\npaths, or pass thresholds. Each evaluator supplies its own relevance data and\nper-cutoff eligibility checks around these common operations.\n\"\"\"\nfrom __future__ import annotations\n\nfrom pathlib import Path\n\nimport numpy as np\nimport pandas as pd\n\n\n__all__ = [\n \"CandidateSet\",\n \"QUALITY_K\",\n \"RankingValidationError\",\n \"REQUIRED_COLUMNS\",\n \"TOP_N\",\n \"ndcg_at_k\",\n \"ranked_items\",\n \"read_ranking\",\n \"score_rankings\",\n \"validate_ranking\",\n]\n\nTOP_N = 100\nQUALITY_K = 10\nREQUIRED_COLUMNS = (\"uid\", \"item_id\", \"rank\")\n\n\nclass RankingValidationError(ValueError):\n \"\"\"Report a ranking-schema or structural-contract violation.\"\"\"\n\n\nclass CandidateSet:\n \"\"\"Provide membership lookups over one packed candidate-set archive.\n\n The archive contains aligned ``uids``, ``item_ids``, and\n ``packed_eligible`` arrays. Candidate column ``c`` is represented by bit\n ``c % 8`` of byte ``c // 8`` using little-endian bit order. Arrays are\n copied into memory so they remain valid after the archive is closed.\n \"\"\"\n\n def __init__(self, path: Path):\n \"\"\"Load an eligibility archive and build ID-to-position indexes.\n\n Args:\n path: Path to a ``.npz`` archive with the candidate-set schema.\n \"\"\"\n with np.load(path, allow_pickle=False) as artifact:\n self.uids = artifact[\"uids\"].astype(np.int64, copy=True)\n self.item_ids = artifact[\"item_ids\"].astype(np.int64, copy=True)\n self.packed = artifact[\"packed_eligible\"].astype(np.uint8, copy=True)\n self.uid_row = {int(uid): row for row, uid in enumerate(self.uids)}\n self.item_column = {\n int(item): column for column, item in enumerate(self.item_ids)\n }\n\n def is_eligible(self, uid: int, item_id: int) -> bool:\n \"\"\"Return whether ``item_id`` is eligible for ``uid``.\n\n IDs absent from the target-user or candidate-item arrays are treated as\n ineligible rather than raising an exception.\n\n Args:\n uid: Target user ID to query.\n item_id: Candidate item ID to query.\n\n Returns:\n ``True`` only when the corresponding packed eligibility bit is set.\n \"\"\"\n row = self.uid_row.get(int(uid))\n column = self.item_column.get(int(item_id))\n if row is None or column is None:\n return False\n byte, bit = divmod(column, 8)\n return bool((int(self.packed[row, byte]) >> bit) & 1)\n\n\ndef read_ranking(path: Path) -> pd.DataFrame:\n \"\"\"Read a parquet or CSV ranking into a pandas frame.\n\n Args:\n path: Input path. A ``.parquet`` suffix selects parquet; every other\n suffix is interpreted as CSV.\n\n Returns:\n The ranking frame as loaded by pandas.\n \"\"\"\n return pd.read_parquet(path) if path.suffix == \".parquet\" else pd.read_csv(path)\n\n\ndef validate_ranking(\n frame: pd.DataFrame,\n targets: set[int],\n) -> pd.DataFrame:\n \"\"\"Normalize and validate the stage-independent ranking contract.\n\n Required values must be finite integers. The user set must exactly match\n ``targets``; every user must have 100 rows, distinct items, and each rank\n from 1 through 100 exactly once. Cutoff-specific candidate eligibility is\n intentionally left to the calling evaluator.\n\n Args:\n frame: Raw ranking frame. Extra columns are discarded from an internal\n copy; the caller's frame is not modified.\n targets: Exact set of target user IDs the ranking must cover.\n\n Returns:\n A normalized frame containing only the required ``int64`` columns.\n\n Raises:\n RankingValidationError: If the ranking violates the shared contract.\n \"\"\"\n required = list(REQUIRED_COLUMNS)\n if not all(column in frame for column in required):\n raise RankingValidationError(f\"submission requires columns {required}\")\n\n normalized = frame[required].copy()\n for column in required:\n numeric = pd.to_numeric(normalized[column], errors=\"coerce\")\n values = numeric.to_numpy(dtype=float)\n if numeric.isna().any() or not np.isfinite(values).all():\n raise RankingValidationError(\n f\"submission {column} must be finite numeric values\"\n )\n if not np.equal(numeric, np.floor(numeric)).all():\n raise RankingValidationError(\n f\"submission {column} must contain integers\"\n )\n normalized[column] = numeric.astype(np.int64)\n\n submitted_users = set(map(int, normalized.uid.unique()))\n if submitted_users != targets:\n raise RankingValidationError(\n f\"submission user set mismatch: missing={len(targets - submitted_users)} \"\n f\"extra={len(submitted_users - targets)}\"\n )\n counts = normalized.groupby(\"uid\").size()\n if not (counts == TOP_N).all():\n raise RankingValidationError(\n f\"submission must contain exactly {TOP_N} rows for every target user\"\n )\n if normalized.duplicated([\"uid\", \"item_id\"]).any():\n raise RankingValidationError(\n \"submission contains duplicate (uid, item_id) pairs\"\n )\n valid_ranks = set(range(1, TOP_N + 1))\n ranks_are_valid = normalized.groupby(\"uid\")[\"rank\"].apply(\n lambda values: set(map(int, values)) == valid_ranks\n )\n if not ranks_are_valid.all():\n raise RankingValidationError(\n f\"each user must have every rank from 1 through {TOP_N} exactly once\"\n )\n return normalized\n\n\ndef ranked_items(frame: pd.DataFrame) -> dict[int, list[int]]:\n \"\"\"Convert a validated ranking frame to ordered items keyed by user.\n\n Args:\n frame: Frame that has passed :func:`validate_ranking`.\n\n Returns:\n A ``uid -> item IDs`` mapping ordered by ascending rank.\n \"\"\"\n ordered = frame.sort_values([\"uid\", \"rank\"])\n return {\n int(uid): list(map(int, values))\n for uid, values in ordered.groupby(\"uid\").item_id\n }\n\n\ndef ndcg_at_k(ranked: list[int], gold: dict[int, int], k: int) -> float:\n \"\"\"Compute graded normalized discounted cumulative gain at ``k``.\n\n Relevance gain is ``2**grade - 1`` and the discount at one-based rank\n ``r`` is ``1 / log2(r + 1)``. Items absent from ``gold`` have grade zero.\n\n Args:\n ranked: Item IDs in predicted rank order.\n gold: Mapping from relevant item IDs to integer relevance grades.\n k: Maximum number of predicted positions to score.\n\n Returns:\n For a valid duplicate-free ranking, NDCG in ``[0, 1]``; returns\n ``0.0`` when the ideal gain is zero.\n \"\"\"\n gains = np.asarray([gold.get(item, 0) for item in ranked[:k]], dtype=np.float64)\n discounts = 1.0 / np.log2(np.arange(2, len(gains) + 2))\n dcg = float(np.sum((np.power(2.0, gains) - 1.0) * discounts))\n ideal = np.asarray(sorted(gold.values(), reverse=True)[:k], dtype=np.float64)\n ideal_discounts = 1.0 / np.log2(np.arange(2, len(ideal) + 2))\n idcg = float(np.sum((np.power(2.0, ideal) - 1.0) * ideal_discounts))\n return dcg / idcg if idcg else 0.0\n\n\ndef score_rankings(\n ranked: dict[int, list[int]],\n graded: dict[int, dict[int, int]],\n) -> dict[str, float | int]:\n \"\"\"Aggregate per-user NDCG@10 over users with relevance labels.\n\n Args:\n ranked: Ranked item IDs for every target user.\n graded: Relevant item grades keyed by user and item.\n\n Returns:\n The six-decimal ``quality_ndcg@10`` value and number of scored users.\n \"\"\"\n quality = float(\n np.mean(\n [\n ndcg_at_k(ranked[uid], gold, QUALITY_K)\n for uid, gold in graded.items()\n ]\n )\n )\n return {\n \"quality_ndcg@10\": round(quality, 6),\n \"quality_users\": len(graded),\n }\n=====EVAL=====\n#!/usr/bin/env python3\n\"\"\"Score a validation-stage ranking against public discovery labels.\n\n``build_task.py`` publishes this module with the solver-visible task files. It\nloads target users, validation eligibility, and validation-window events from\nthe adjacent ``data`` directory, then evaluates one ranking supplied on the\ncommand line. Stage-independent mechanics come from the adjacent public\n``ranking_evaluation.py`` module. The builder installs the same checked-in\nmodule in the private judge, so public and private scoring mechanics cannot\ndrift. A relevant candidate receives grade 3 for an organic like or grade 1 for\nan organic listen with at least 80 percent completion; a like takes precedence\nwhen both events exist.\n\nBefore scoring, the ranking must contain exactly 100 distinct eligible items\nfor every target user, with integer-valued ``uid``, ``item_id``, and ``rank``\ncolumns and ranks 1 through 100 exactly once per user. Extra columns are\nignored. Quality is graded NDCG@10, averaged only over users who have at least\none eligible relevant item in the validation window.\n\nThe evaluator prints a JSON object containing the model path and scores. It\ndoes not apply the task's pass threshold; its purpose is model development and\nselection. The private judge applies the threshold to the final submission.\n\nUsage::\n\n python evaluate_public.py \n\"\"\"\nfrom __future__ import annotations\n\nimport json\nimport sys\nfrom pathlib import Path\n\nimport pandas as pd\n\nfrom ranking_evaluation import (\n CandidateSet,\n RankingValidationError,\n ranked_items,\n read_ranking,\n score_rankings,\n validate_ranking,\n)\n\n\nHERE = Path(__file__).resolve().parent\nDATA = HERE / \"data\"\nLISTEN_STRONG = 80\n\n\ndef validation_truth(\n eligibility: CandidateSet, targets: set[int]\n) -> dict[int, dict[int, int]]:\n \"\"\"Build cutoff-correct graded relevance from public validation events.\n\n Only target-user events for eligible candidates are retained. Organic\n listens completed to at least 80 percent receive grade 1, and organic likes\n receive grade 3. Repeated user-item events are collapsed, and processing\n likes second ensures that grade 3 wins over grade 1.\n\n Args:\n eligibility: Validation-cutoff candidate membership service.\n targets: Complete set of target user IDs.\n\n Returns:\n A nested ``uid -> item_id -> grade`` mapping. Users without an eligible\n relevant event are omitted.\n \"\"\"\n listens = pd.read_parquet(DATA / \"val_listens.parquet\")\n likes = pd.read_parquet(DATA / \"val_likes.parquet\")\n strong = listens[\n listens.uid.isin(targets)\n & (listens.is_organic == 1)\n & (listens.played_ratio_pct >= LISTEN_STRONG)\n ][[\"uid\", \"item_id\"]].drop_duplicates()\n organic_likes = likes[\n likes.uid.isin(targets) & (likes.is_organic == 1)\n ][[\"uid\", \"item_id\"]].drop_duplicates()\n\n graded: dict[int, dict[int, int]] = {}\n for raw_uid, raw_item in strong.itertuples(index=False, name=None):\n uid, item = int(raw_uid), int(raw_item)\n if eligibility.is_eligible(uid, item):\n graded.setdefault(uid, {})[item] = 1\n for raw_uid, raw_item in organic_likes.itertuples(index=False, name=None):\n uid, item = int(raw_uid), int(raw_item)\n if eligibility.is_eligible(uid, item):\n graded.setdefault(uid, {})[item] = 3\n return graded\n\n\ndef load_submission(\n path: Path, eligibility: CandidateSet, targets: set[int]\n) -> dict[int, list[int]]:\n \"\"\"Load and validate a public validation ranking.\n\n Files ending in ``.parquet`` are read as parquet; every other suffix is\n read as CSV. The required columns must be integer-valued, cover exactly the\n target-user set, contain 100 rows and ranks 1 through 100 per user, avoid\n duplicate user-item pairs, and contain only cutoff-eligible items.\n\n Args:\n path: Ranking file to read.\n eligibility: Validation-cutoff candidate membership service.\n targets: Exact set of users the ranking must cover.\n\n Returns:\n A ``uid -> ranked item IDs`` mapping ordered by ascending rank.\n\n Raises:\n ValueError: If the ranking violates the required schema or invariants.\n \"\"\"\n frame = validate_ranking(read_ranking(path), targets)\n if not all(\n eligibility.is_eligible(uid, item)\n for uid, item in frame[[\"uid\", \"item_id\"]].itertuples(index=False, name=None)\n ):\n raise RankingValidationError(\n \"submission contains an item rejected by eligibility service\"\n )\n return ranked_items(frame)\n\n\ndef score(\n ranked: dict[int, list[int]],\n graded: dict[int, dict[int, int]],\n) -> dict[str, float | int]:\n \"\"\"Aggregate per-user NDCG@10 over users with public relevance labels.\n\n Args:\n ranked: Ranked item IDs for every target user.\n graded: Eligible validation relevance keyed by user and item.\n\n Returns:\n The six-decimal ``quality_ndcg@10`` value and number of scored users.\n \"\"\"\n return score_rankings(ranked, graded)\n\n\ndef main() -> None:\n \"\"\"Run the public evaluator CLI and print its JSON score report.\"\"\"\n targets_frame = pd.read_parquet(DATA / \"target_users.parquet\")\n targets = set(targets_frame.uid.astype(int))\n eligibility = CandidateSet(DATA / \"validation_eligible_candidates.npz\")\n graded = validation_truth(eligibility, targets)\n\n if len(sys.argv) != 2:\n raise SystemExit(\n \"usage: evaluate_public.py \"\n )\n path = Path(sys.argv[1])\n ranked = load_submission(path, eligibility, targets)\n print(json.dumps({\"model\": str(path), \"scores\": score(ranked, graded)}, indent=2))\n\n\nif __name__ == \"__main__\":\n main()",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:33:21.722Z",
"data": {
"type": "total_tokens_reminder",
"text": "14981728 tokens left"
}
}
]
},
{
"id": 3,
"role": "agent",
"timestamp": "2026-08-29T02:33:23.412Z",
"blocks": [
{
"kind": "reasoning",
"timestamp": "2026-08-29T02:33:23.412Z",
"text": ""
},
{
"kind": "tool",
"timestamp": "2026-08-29T02:33:25.614Z",
"callId": "toolu_01W6qEueC7ioyMs7n8rg9x3u",
"name": "Bash",
"input": {
"command": "mkdir -p solution && python -c \"\nimport pandas as pd, numpy as np, time\nt=time.time()\nfor f in ['candidate_catalog','target_users','validation_preference_state','test_preference_state','val_likes','val_listens','train_likes']:\n d=pd.read_parquet('/task/data/%s.parquet'%f)\n print(f, d.shape, list(d.columns))\n print(d.head(3))\nprint(time.time()-t)\n\"",
"description": "Inspect small parquet files"
},
"result": {
"timestamp": "2026-08-29T02:33:27.389Z",
"content": "candidate_catalog (30000, 4) ['item_id', 'positive_listens', 'organic_positive_listens', 'popularity_rank']\n item_id positive_listens organic_positive_listens popularity_rank\n0 5862961 26615 20620 1\n1 6901374 25536 17347 2\n2 5635052 24691 17194 3\ntarget_users (8456, 3) ['uid', 'recent_positive_listens', 'history_positive_listens']\n uid recent_positive_listens history_positive_listens\n0 100 844.0 2604\n1 200 50.0 286\n2 300 168.0 359\nvalidation_preference_state (469124, 3) ['uid', 'item_id', 'state']\n uid item_id state\n0 100 410868 liked\n1 100 732449 liked\n2 100 982903 liked\ntest_preference_state (484776, 3) ['uid', 'item_id', 'state']\n uid item_id state\n0 100 410868 liked\n1 100 732449 liked\n2 100 982903 liked\nval_likes (37795, 4) ['uid', 'timestamp', 'item_id', 'is_organic']\n uid timestamp item_id is_organic\n0 100 25249855 3526521 1\n1 300 25046245 4867327 1\n2 300 25046970 2674136 1\nval_listens (1501697, 6) ['uid', 'timestamp', 'item_id', 'is_organic', 'played_ratio_pct', 'track_length_seconds']\n uid timestamp item_id is_organic played_ratio_pct track_length_seconds\n0 100 24943430 9321269 0 100 195\n1 100 24943605 5452713 0 100 175\n2 100 24943765 6448777 0 100 160\ntrain_likes (814831, 4) ['uid', 'timestamp', 'item_id', 'is_organic']\n uid timestamp item_id is_organic\n0 100 44755 732449 1\n1 100 1155860 6568592 0\n2 100 1259125 5411243 1\n0.16102170944213867",
"isError": false
}
},
{
"kind": "tool",
"timestamp": "2026-08-29T02:33:27.425Z",
"callId": "toolu_01Nz9XKb2LTmdjd6NkL1WVqY",
"name": "Bash",
"input": {
"command": "python -c \"\nimport numpy as np,time\nt=time.time()\nz=np.load('/task/data/validation_eligible_candidates.npz')\nprint(list(z.keys()))\nfor k in z: print(k, z[k].shape, z[k].dtype)\nu=z['uids']; it=z['item_ids']; p=z['packed_eligible']\nm=np.unpackbits(p,axis=1,count=len(it),bitorder='little')\nprint('elig per user mean',m.sum(1).mean(), m.sum(1).min(), m.sum(1).max())\nprint(time.time()-t)\n\"",
"description": "Inspect candidate npz"
},
"result": {
"timestamp": "2026-08-29T02:33:28.332Z",
"content": "['uids', 'item_ids', 'packed_eligible']\nuids (8456,) uint32\nitem_ids (30000,) uint32\npacked_eligible (8456, 3750) uint8\nelig per user mean 29067.306291390727 24657 30000\n0.5634770393371582",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:33:28.335Z",
"data": {
"type": "total_tokens_reminder",
"text": "14974212 tokens left"
}
}
]
},
{
"id": 4,
"role": "agent",
"timestamp": "2026-08-29T02:33:39.858Z",
"blocks": [
{
"kind": "reasoning",
"timestamp": "2026-08-29T02:33:39.858Z",
"text": ""
},
{
"kind": "tool",
"timestamp": "2026-08-29T02:33:40.932Z",
"callId": "toolu_01PxFeAaYPdyffbkKouaB8yJ",
"name": "Bash",
"input": {
"command": "cd /app/solution && python -c \"\nimport pyarrow.parquet as pq, time\nf=pq.ParquetFile('/task/data/train_listens.parquet')\nprint(f.metadata)\nprint(f.schema)\n\"",
"description": "Check train_listens metadata"
},
"result": {
"timestamp": "2026-08-29T02:33:41.426Z",
"content": "\n created_by: parquet-cpp-arrow version 18.1.0\n num_columns: 6\n num_rows: 43484159\n num_row_groups: 42\n format_version: 2.6\n serialized_size: 25540\n\nrequired group field_id=-1 schema {\n optional int32 field_id=-1 uid (Int(bitWidth=32, isSigned=false));\n optional int32 field_id=-1 timestamp (Int(bitWidth=32, isSigned=false));\n optional int32 field_id=-1 item_id (Int(bitWidth=32, isSigned=false));\n optional int32 field_id=-1 is_organic (Int(bitWidth=8, isSigned=false));\n optional int32 field_id=-1 played_ratio_pct (Int(bitWidth=16, isSigned=false));\n optional int32 field_id=-1 track_length_seconds (Int(bitWidth=32, isSigned=false));\n}",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:33:41.428Z",
"data": {
"type": "total_tokens_reminder",
"text": "14972503 tokens left"
}
}
]
},
{
"id": 5,
"role": "agent",
"timestamp": "2026-08-29T02:33:46.392Z",
"blocks": [
{
"kind": "reasoning",
"timestamp": "2026-08-29T02:33:46.392Z",
"text": ""
},
{
"kind": "tool",
"timestamp": "2026-08-29T02:33:46.763Z",
"callId": "toolu_01QkQ1B5ueUVY12Qw3ZxZh4F",
"name": "Bash",
"input": {
"command": "free -g; nproc; python -c \"import torch;print(torch.__version__, torch.get_num_threads())\"",
"description": "Check resources"
},
"result": {
"timestamp": "2026-08-29T02:33:49.811Z",
"content": " total used free shared buff/cache available\nMem: 15 1 0 0 13 14\nSwap: 0 0 0\n8\n2.8.0+cpu 4",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:33:49.814Z",
"data": {
"type": "total_tokens_reminder",
"text": "14971698 tokens left"
}
}
]
},
{
"id": 6,
"role": "agent",
"timestamp": "2026-08-29T02:33:55.975Z",
"blocks": [
{
"kind": "reasoning",
"timestamp": "2026-08-29T02:33:55.975Z",
"text": ""
},
{
"kind": "tool",
"timestamp": "2026-08-29T02:34:03.356Z",
"callId": "toolu_01LpSGAwg7rVuTnimehE3mga",
"name": "Write",
"input": {
"file_path": "/app/solution/data_utils.py",
"content": "\"\"\"Shared data loading helpers for the two-tower discovery ranker.\"\"\"\nfrom __future__ import annotations\n\nfrom pathlib import Path\n\nimport numpy as np\nimport pandas as pd\nimport pyarrow.parquet as pq\n\nDATA = Path(\"/task/data\")\nTRAIN_CUTOFF = 24786800\nDAY = 86400\n\n\ndef load_listens(split: str, min_ratio: int = 0, since: int | None = None,\n organic_only: bool = False) -> pd.DataFrame:\n \"\"\"Stream a listens parquet row-group at a time with early filtering.\"\"\"\n cols = [\"uid\", \"timestamp\", \"item_id\", \"is_organic\", \"played_ratio_pct\"]\n reader = pq.ParquetFile(DATA / f\"{split}_listens.parquet\")\n parts = []\n for rg in range(reader.metadata.num_row_groups):\n tbl = reader.read_row_group(rg, columns=cols)\n df = tbl.to_pandas()\n if min_ratio:\n df = df[df.played_ratio_pct.values >= min_ratio]\n if since is not None:\n df = df[df.timestamp.values >= since]\n if organic_only:\n df = df[df.is_organic.values == 1]\n parts.append(df)\n out = pd.concat(parts, ignore_index=True)\n return out\n\n\ndef load_events(family: str, split: str) -> pd.DataFrame:\n return pd.read_parquet(DATA / f\"{split}_{family}.parquet\")\n\n\ndef candidate_items() -> np.ndarray:\n cat = pd.read_parquet(DATA / \"candidate_catalog.parquet\")\n return cat\n\n\ndef target_users() -> np.ndarray:\n return pd.read_parquet(DATA / \"target_users.parquet\").uid.astype(np.int64).values\n\n\ndef eligibility_matrix(stage: str):\n \"\"\"Return (uids, item_ids, bool mask [n_users, n_items]).\"\"\"\n with np.load(DATA / f\"{stage}_eligible_candidates.npz\", allow_pickle=False) as z:\n uids = z[\"uids\"].astype(np.int64)\n item_ids = z[\"item_ids\"].astype(np.int64)\n packed = z[\"packed_eligible\"]\n mask = np.unpackbits(packed, axis=1, count=len(item_ids),\n bitorder=\"little\").astype(bool)\n return uids, item_ids, mask\n"
},
"result": {
"timestamp": "2026-08-29T02:34:03.368Z",
"content": "File created successfully at: /app/solution/data_utils.py (file state is current in your context — no need to Read it back)",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:34:03.369Z",
"data": {
"type": "total_tokens_reminder",
"text": "14970448 tokens left"
}
}
]
},
{
"id": 7,
"role": "agent",
"timestamp": "2026-08-29T02:34:10.100Z",
"blocks": [
{
"kind": "tool",
"timestamp": "2026-08-29T02:34:10.100Z",
"callId": "toolu_014n6ba7fMnJuU4jGAzKDvC8",
"name": "Bash",
"input": {
"command": "time python -c \"\nimport numpy as np, pandas as pd, data_utils as du\ntg = set(du.target_users().tolist())\nuids, items, mask = du.eligibility_matrix('validation')\nitempos = {int(i):c for c,i in enumerate(items)}\n# val relevance\nvl = du.load_events('listens','val')\nvlk = du.load_events('likes','val')\nstrong = vl[(vl.is_organic==1)&(vl.played_ratio_pct>=80)&vl.uid.isin(tg)][['uid','item_id']].drop_duplicates()\nlk = vlk[(vlk.is_organic==1)&vlk.uid.isin(tg)][['uid','item_id']].drop_duplicates()\nrel = pd.concat([strong,lk]).drop_duplicates()\nprint('rel pairs', len(rel), 'users', rel.uid.nunique())\nincat = rel.item_id.isin(itempos.keys()).mean()\nprint('rel in catalog frac', incat)\n# eligible frac\nurow={int(u):r for r,u in enumerate(uids)}\nrr = rel[rel.item_id.isin(itempos.keys())]\nr_idx = rr.uid.map(urow).values; c_idx=rr.item_id.map(itempos).values\nel = mask[r_idx,c_idx]\nprint('eligible frac of in-cat rel', el.mean())\nnp.save('/tmp/nothing.npy',np.array([0]))\n\" 2>&1 | tail -20",
"description": "Diagnose relevance coverage"
},
"result": {
"timestamp": "2026-08-29T02:34:12.211Z",
"content": "rel pairs 266887 users 6511\nrel in catalog frac 0.6584397141861537\neligible frac of in-cat rel 0.2149275304588315\n\nreal\t0m2.092s\nuser\t0m2.554s\nsys\t0m0.345s",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:34:12.213Z",
"data": {
"type": "total_tokens_reminder",
"text": "14969794 tokens left"
}
}
]
},
{
"id": 8,
"role": "agent",
"timestamp": "2026-08-29T02:34:36.685Z",
"blocks": [
{
"kind": "reasoning",
"timestamp": "2026-08-29T02:34:36.685Z",
"text": ""
},
{
"kind": "tool",
"timestamp": "2026-08-29T02:34:39.922Z",
"callId": "toolu_0131xYPmrNijn5TUmU2QLoni",
"name": "Bash",
"input": {
"command": "time python -c \"\nimport numpy as np, pandas as pd, data_utils as du\nuids, items, mask = du.eligibility_matrix('validation')\nuids2, items2, mask2 = du.eligibility_matrix('test')\nprint('same uids', np.array_equal(uids,uids2), 'same items', np.array_equal(items,items2))\nprint('val elig',mask.sum(1).mean(),'test elig',mask2.sum(1).mean())\nprint('test subset of val?', (mask2 & ~mask).sum())\n# check excluded = history\ntg=du.target_users()\nprint('uids==targets sorted', np.array_equal(np.sort(uids), np.sort(tg)))\n\"",
"description": "Compare eligibility stages"
},
"result": {
"timestamp": "2026-08-29T02:34:42.244Z",
"content": "same uids True same items True\nval elig 29067.306291390727 test elig 29041.3178807947\ntest subset of val? 0\nuids==targets sorted True\n\nreal\t0m2.308s\nuser\t0m2.653s\nsys\t0m0.365s",
"isError": false
}
},
{
"kind": "tool",
"timestamp": "2026-08-29T02:34:43.067Z",
"callId": "toolu_01HeBAiar6SgxRgAHy5FozYV",
"name": "Bash",
"input": {
"command": "time python -c \"\nimport numpy as np, pandas as pd, data_utils as du, time\nt=time.time()\ndf = du.load_listens('train', min_ratio=50, since=du.TRAIN_CUTOFF-180*86400)\nprint('rows',len(df), time.time()-t)\nprint('users', df.uid.nunique(), 'items', df.item_id.nunique())\nvc = df.item_id.value_counts()\nprint(vc.head())\nprint('items with >=20 plays', (vc>=20).sum(), '>=50', (vc>=50).sum(), '>=100',(vc>=100).sum())\ncat=du.candidate_items()\nprint('catalog coverage of rows', df.item_id.isin(set(cat.item_id)).mean())\n\" ",
"description": "Load recent train listens stats"
},
"result": {
"timestamp": "2026-08-29T02:34:47.590Z",
"content": "rows 19038702 1.1295807361602783\nusers 9108 items 516265\nitem_id\n5862961 26615\n3542184 24075\n9378983 24036\n6901374 23640\n2651314 16286\nName: count, dtype: int64\nitems with >=20 plays 100552 >=50 54936 >=100 32278\ncatalog coverage of rows 0.7359914557200381\n\nreal\t0m4.505s\nuser\t0m5.145s\nsys\t0m0.756s",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:34:47.592Z",
"data": {
"type": "total_tokens_reminder",
"text": "14967523 tokens left"
}
}
]
},
{
"id": 9,
"role": "agent",
"timestamp": "2026-08-29T02:35:27.730Z",
"blocks": [
{
"kind": "reasoning",
"timestamp": "2026-08-29T02:35:27.730Z",
"text": ""
},
{
"kind": "message",
"timestamp": "2026-08-29T02:35:28.433Z",
"text": "Data understood: 9,108 users, 43M listens, eligibility excludes already-consumed items (true discovery). Writing the pipeline."
},
{
"kind": "tool",
"timestamp": "2026-08-29T02:36:00.082Z",
"callId": "toolu_015DkCYB5YyTbJxSav7Ggypc",
"name": "Write",
"input": {
"file_path": "/app/solution/features.py",
"content": "\"\"\"Build cutoff-correct user history channels and training targets.\n\nEvery representation consumed by the user tower is a bag of item ids drawn\nstrictly from events before the relevant cutoff, so the same code path serves\ntraining slices, the validation ranking, and the final hidden-test ranking.\n\"\"\"\nfrom __future__ import annotations\n\nimport numpy as np\nimport pandas as pd\n\nimport data_utils as du\n\nDAY = 86400\n# Channel capacities: recent positive listens, habitual top items, likes,\n# dislikes.\nCH_SIZES = (192, 96, 96, 32)\nN_CH = 4\n\n\ndef _sorted_events(df: pd.DataFrame) -> tuple[np.ndarray, np.ndarray, np.ndarray]:\n \"\"\"Return uid-major, time-ordered (uid, ts, item) arrays.\"\"\"\n order = np.lexsort((df.timestamp.values, df.uid.values))\n return (df.uid.values[order].astype(np.int64),\n df.timestamp.values[order].astype(np.int64),\n df.item_id.values[order].astype(np.int64))\n\n\nclass EventStore:\n \"\"\"Per-user, time-sorted event streams with cutoff slicing.\"\"\"\n\n def __init__(self, frames: dict[str, pd.DataFrame], users: np.ndarray):\n self.users = users\n self.upos = {int(u): i for i, u in enumerate(users)}\n self.streams = {}\n for name, df in frames.items():\n df = df[df.uid.isin(self.upos)]\n uid, ts, item = _sorted_events(df)\n row = np.array([self.upos[int(u)] for u in uid], dtype=np.int64) \\\n if len(uid) else np.zeros(0, np.int64)\n # user boundaries\n starts = np.searchsorted(row, np.arange(len(users)), \"left\")\n ends = np.searchsorted(row, np.arange(len(users)), \"right\")\n self.streams[name] = (ts, item, starts, ends)\n\n def slice(self, name: str, u: int, cutoff: int):\n ts, item, starts, ends = self.streams[name]\n s, e = starts[u], ends[u]\n if s == e:\n return ts[0:0], item[0:0]\n p = s + np.searchsorted(ts[s:e], cutoff, \"left\")\n return ts[s:p], item[s:p]\n\n\ndef build_profiles(store: EventStore, vocab_map: np.ndarray, cutoff: int,\n half_life_days: float = 21.0):\n \"\"\"Return padded id/weight tensors for all users at ``cutoff``.\n\n Args:\n store: Event store holding listens/likes/dislikes streams.\n vocab_map: Dense lookup from raw item id to vocab index (-1 = unknown).\n cutoff: Exclusive upper bound on event timestamps.\n half_life_days: Recency half-life for the recent-listen channel.\n\n Returns:\n ``(ids, weights, seen)`` where ``ids``/``weights`` are lists of\n ``[n_users, cap]`` arrays (one per channel) and ``seen`` is a list of\n per-user sets of already-consumed vocab indices.\n \"\"\"\n n = len(store.users)\n ids = [np.zeros((n, c), np.int64) for c in CH_SIZES]\n wts = [np.zeros((n, c), np.float32) for c in CH_SIZES]\n seen: list[np.ndarray] = []\n hl = half_life_days * DAY\n\n for u in range(n):\n lts, litem = store.slice(\"listen\", u, cutoff)\n lidx = vocab_map[litem]\n ok = lidx >= 0\n lidx_ok, lts_ok = lidx[ok], lts[ok]\n\n # Channel 0: most recent positive listens, recency weighted.\n c = CH_SIZES[0]\n take = lidx_ok[-c:]\n tts = lts_ok[-c:]\n if take.size:\n w = np.exp2(-(cutoff - tts) / hl).astype(np.float32)\n ids[0][u, :take.size] = take\n wts[0][u, :take.size] = w / max(w.sum(), 1e-6)\n\n # Channel 1: habitual favourites -- top items by lifetime play count.\n c = CH_SIZES[1]\n if lidx_ok.size:\n uniq, cnt = np.unique(lidx_ok, return_counts=True)\n if uniq.size > c:\n sel = np.argpartition(-cnt, c - 1)[:c]\n uniq, cnt = uniq[sel], cnt[sel]\n w = np.log1p(cnt).astype(np.float32)\n ids[1][u, :uniq.size] = uniq\n wts[1][u, :uniq.size] = w / max(w.sum(), 1e-6)\n seen.append(np.unique(lidx_ok))\n else:\n seen.append(np.zeros(0, np.int64))\n\n # Channels 2/3: explicit feedback.\n for ci, name in ((2, \"like\"), (3, \"dislike\")):\n c = CH_SIZES[ci]\n _, eitem = store.slice(name, u, cutoff)\n eidx = vocab_map[eitem]\n eidx = eidx[eidx >= 0][-c:]\n if eidx.size:\n ids[ci][u, :eidx.size] = eidx\n wts[ci][u, :eidx.size] = 1.0 / eidx.size\n return ids, wts, seen\n\n\ndef build_targets(store: EventStore, vocab_map: np.ndarray, n_catalog: int,\n cutoff: int, horizon: int, seen: list[np.ndarray]):\n \"\"\"Collect new-item organic positives in ``(cutoff, cutoff + horizon]``.\n\n Mirrors the evaluation objective: grade-3 organic likes and grade-1\n organic 80%-completion listens on items the user has not consumed before\n the cutoff.\n \"\"\"\n rows_u, rows_i, rows_w = [], [], []\n for u in range(len(store.users)):\n hi = cutoff + horizon\n got: dict[int, float] = {}\n for name, weight in ((\"strong\", 1.0), (\"like_org\", 2.0)):\n ts, item, starts, ends = store.streams[name]\n s, e = starts[u], ends[u]\n if s == e:\n continue\n a = s + np.searchsorted(ts[s:e], cutoff, \"right\")\n b = s + np.searchsorted(ts[s:e], hi, \"right\")\n if a >= b:\n continue\n idx = vocab_map[item[a:b]]\n idx = idx[(idx >= 0) & (idx < n_catalog)]\n for it in np.unique(idx):\n got[int(it)] = max(got.get(int(it), 0.0), weight)\n if not got:\n continue\n prior = seen[u]\n cand = np.fromiter(got.keys(), np.int64, len(got))\n keep = ~np.isin(cand, prior)\n for it in cand[keep]:\n rows_u.append(u)\n rows_i.append(int(it))\n rows_w.append(got[int(it)])\n return (np.asarray(rows_u, np.int64), np.asarray(rows_i, np.int64),\n np.asarray(rows_w, np.float32))\n\n\ndef load_frames(include_val: bool):\n \"\"\"Load listen/like/dislike frames, optionally including the val window.\"\"\"\n splits = [\"train\"] + ([\"val\"] if include_val else [])\n listens, likes, dislikes = [], [], []\n for sp in splits:\n since = du.TRAIN_CUTOFF - 200 * DAY if sp == \"train\" else None\n listens.append(du.load_listens(sp, min_ratio=50, since=since))\n likes.append(du.load_events(\"likes\", sp))\n dislikes.append(du.load_events(\"dislikes\", sp))\n lis = pd.concat(listens, ignore_index=True)\n lik = pd.concat(likes, ignore_index=True)\n dis = pd.concat(dislikes, ignore_index=True)\n strong = lis[(lis.is_organic.values == 1) & (lis.played_ratio_pct.values >= 80)]\n frames = {\n \"listen\": lis[[\"uid\", \"timestamp\", \"item_id\"]],\n \"like\": lik[[\"uid\", \"timestamp\", \"item_id\"]],\n \"dislike\": dis[[\"uid\", \"timestamp\", \"item_id\"]],\n \"strong\": strong[[\"uid\", \"timestamp\", \"item_id\"]],\n \"like_org\": lik[lik.is_organic.values == 1][[\"uid\", \"timestamp\", \"item_id\"]],\n }\n return frames, lis\n\n\ndef build_vocab(listens: pd.DataFrame, catalog: pd.DataFrame, extra: int = 50000):\n \"\"\"Catalog items first, then the most played non-catalog history items.\"\"\"\n cat_items = catalog.item_id.astype(np.int64).values\n n_catalog = len(cat_items)\n vc = listens.item_id.value_counts()\n non_cat = vc[~vc.index.isin(set(cat_items.tolist()))]\n extra_items = non_cat.index.values[:extra].astype(np.int64)\n vocab = np.concatenate([cat_items, extra_items])\n vmax = int(vocab.max()) + 1\n vocab_map = np.full(vmax, -1, np.int64)\n vocab_map[vocab] = np.arange(len(vocab))\n return vocab, vocab_map, n_catalog\n"
},
"result": {
"timestamp": "2026-08-29T02:36:00.091Z",
"content": "File created successfully at: /app/solution/features.py (file state is current in your context — no need to Read it back)",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:36:00.098Z",
"data": {
"type": "total_tokens_reminder",
"text": "14961214 tokens left"
}
}
]
},
{
"id": 10,
"role": "agent",
"timestamp": "2026-08-29T02:36:05.158Z",
"blocks": [
{
"kind": "reasoning",
"timestamp": "2026-08-29T02:36:05.158Z",
"text": ""
},
{
"kind": "tool",
"timestamp": "2026-08-29T02:36:09.155Z",
"callId": "toolu_012Mwx57BRDaaD3vyafjnYop",
"name": "Bash",
"input": {
"command": "python - <<'EOF'\nimport re\np='features.py'\ns=open(p).read()\ns = s.replace(\"\"\"def _sorted_events\"\"\", \"\"\"def _map(vocab_map: np.ndarray, items: np.ndarray) -> np.ndarray:\n \\\"\\\"\\\"Vocab lookup that tolerates item ids beyond the lookup table.\\\"\\\"\\\"\n if items.size == 0:\n return items.astype(np.int64)\n it = items.astype(np.int64)\n out = np.full(it.shape, -1, np.int64)\n ok = it < vocab_map.shape[0]\n out[ok] = vocab_map[it[ok]]\n return out\n\n\ndef _sorted_events\"\"\")\ns = s.replace(\"lidx = vocab_map[litem]\", \"lidx = _map(vocab_map, litem)\")\ns = s.replace(\"eidx = vocab_map[eitem]\", \"eidx = _map(vocab_map, eitem)\")\ns = s.replace(\"idx = vocab_map[item[a:b]]\", \"idx = _map(vocab_map, item[a:b])\")\nopen(p,'w').write(s)\nEOF\ngrep -n \"_map\" features.py",
"description": "Add safe vocab lookup"
},
"result": {
"timestamp": "2026-08-29T02:36:09.237Z",
"content": "21:def _map(vocab_map: np.ndarray, items: np.ndarray) -> np.ndarray:\n27: ok = it < vocab_map.shape[0]\n28: out[ok] = vocab_map[it[ok]]\n66:def build_profiles(store: EventStore, vocab_map: np.ndarray, cutoff: int,\n72: vocab_map: Dense lookup from raw item id to vocab index (-1 = unknown).\n89: lidx = _map(vocab_map, litem)\n120: eidx = _map(vocab_map, eitem)\n128:def build_targets(store: EventStore, vocab_map: np.ndarray, n_catalog: int,\n149: idx = _map(vocab_map, item[a:b])\n198: vocab_map = np.full(vmax, -1, np.int64)\n199: vocab_map[vocab] = np.arange(len(vocab))\n200: return vocab, vocab_map, n_catalog",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:36:09.242Z",
"data": {
"type": "edited_text_file",
"filename": "/app/solution/features.py",
"snippet": "1\t\"\"\"Build cutoff-correct user history channels and training targets.\n2\t\n3\tEvery representation consumed by the user tower is a bag of item ids drawn\n4\tstrictly from events before the relevant cutoff, so the same code path serves\n5\ttraining slices, the validation ranking, and the final hidden-test ranking.\n6\t\"\"\"\n7\tfrom __future__ import annotations\n8\t\n9\timport numpy as np\n10\timport pandas as pd\n11\t\n12\timport data_utils as du\n13\t\n14\tDAY = 86400\n15\t# Channel capacities: recent positive listens, habitual top items, likes,\n16\t# dislikes.\n17\tCH_SIZES = (192, 96, 96, 32)\n18\tN_CH = 4\n19\t\n20\t\n21\tdef _map(vocab_map: np.ndarray, items: np.ndarray) -> np.ndarray:\n22\t \"\"\"Vocab lookup that tolerates item ids beyond the lookup table.\"\"\"\n23\t if items.size == 0:\n24\t return items.astype(np.int64)\n25\t it = items.astype(np.int64)\n26\t out = np.full(it.shape, -1, np.int64)\n27\t ok = it < vocab_map.shape[0]\n28\t out[ok] = vocab_map[it[ok]]\n29\t return out\n30\t\n31\t\n32\tdef _sorted_events(df: pd.DataFrame) -> tuple[np.ndarray, np.ndarray, np.ndarray]:\n33\t \"\"\"Return uid-major, time-ordered (uid, ts, item) arrays.\"\"\"\n34\t order = np.lexsort((df.timestamp.values, df.uid.values))\n35\t return (df.uid.values[order].astype(np.int64),\n36\t df.timestamp.values[order].astype(np.int64),\n37\t df.item_id.values[order].astype(np.int64))\n38\t\n39\t\n40\tclass EventStore:\n41\t \"\"\"Per-user, time-sorted event streams with cutoff slicing.\"\"\"\n42\t\n43\t def __init__(self, frames: dict[str, pd.DataFrame], users: np.ndarray):\n44\t self.users = users\n45\t self.upos = {int(u): i for i, u in enumerate(users)}\n46\t self.streams = {}\n47\t for name, df in frames.items():\n48\t df = df[df.uid.isin(self.upos)]\n49\t uid, ts, item = _sorted_events(df)\n50\t row = np.array([self.upos[int(u)] for u in uid], dtype=np.int64) \\\n51\t if len(uid) else np.zeros(0, np.int64)\n52\t # user boundaries\n53\t starts = np.searchsorted(row, np.arange(len(users)), \"left\")\n54\t ends = np.searchsorted(row, np.arange(len(users)), \"right\")\n55\t self.streams[name] = (ts, item, starts, ends)\n56\t\n57\t def slice(self, name: str, u: int, cutoff: int):\n58\t ts, item, starts, ends = self.streams[name]\n59\t s, e = starts[u], ends[u]\n60\t if s == e:\n61\t return ts[0:0], item[0:0]\n62\t p = s + np.searchsorted(ts[s:e], cutoff, \"left\")\n63\t return ts[s:p], item[s:p]\n64\t\n65\t\n66\tdef build_profiles(store: EventStore, vocab_map: np.ndarray, cutoff: int,\n67\t half_life_days: float = 21.0):\n68\t \"\"\"Return padded id/weight tensors for all users at ``cutoff``.\n69\t\n70\t Args:\n71\t store: Event store holding listens/likes/dislikes streams.\n72\t vocab_map: Dense lookup from raw item id to vocab index (-1 = unknown).\n73\t cutoff: Exclusive upper bound on event timestamps.\n74\t half_life_days: Recency half-life for the recent-listen channel.\n75\t\n76\t Returns:\n77\t ``(ids, weights, seen)`` where ``ids``/``weights`` are lists of\n78\t ``[n_users, cap]`` arrays (one per channel) and ``seen`` is a list of\n79\t per-user sets of already-consumed vocab indices.\n80\t \"\"\"\n81\t n = len(store.users)\n82\t ids = [np.zeros((n, c), np.int64) for c in CH_SIZES]\n83\t wts = [np.zeros((n, c), np.float32) for c in CH_SIZES]\n84\t seen: list[np.ndarray] = []\n85\t hl = half_life_days * DAY\n86\t\n87\t for u in range(n):\n88\t lts, litem = store.slice(\"listen\", u, cutoff)\n89\t lidx = _map(vocab_map, litem)\n90\t ok = lidx >= 0\n91\t lidx_ok, lts_ok = lidx[ok], lts[ok]\n92\t\n93\t # Channel 0: most recent positive listens, recency weighted.\n94\t c = CH_SIZES[0]\n95\t take = lidx_ok[-c:]\n96\t tts = lts_ok[-c:]\n97\t if take.size:\n98\t w = np.exp2(-(cutoff - tts) / hl).astype(np.float32)\n99\t ids[0][u, :take.size] = take\n100\t wts[0][u, :take.size] = w / max(w.sum(), 1e-6)\n101\t\n102\t # Channel 1: habitual favourites -- top items by lifetime play count.\n103\t c = CH_SIZES[1]\n104\t if lidx_ok.size:\n105\t uniq, cnt = np.unique(lidx_ok, return_counts=True)\n106\t if uniq.size > c:\n107\t sel = np.argpartition(-cnt, c - 1)[:c]\n108\t uniq, cnt = uniq[sel], cnt[sel]\n109\t w = np.log1p(cnt).astype(np.float32)\n110\t ids[1][u, :uniq.size] = uniq\n111\t wts[1][u, :uniq.size] = w / max(w.sum(), 1e-6)\n112\t seen.append(np.unique(lidx_ok))\n113\t else:\n114\t seen.append(np.zeros(0, np.int64))\n115\t\n116\t # Channels 2/3: explicit feedback.\n117\t for ci, name in ((2, \"like\"), (3, \"dislike\")):\n118\t c = CH_SIZES[ci]\n119\t _, eitem = store.slice(name, u, cutoff)\n120\t eidx = _map(vocab_map, eitem)\n121\t eidx = eidx[eidx >= 0][-c:]\n122\t if eidx.size:\n123\t ids[ci][u, :eidx.size] = eidx\n124\t wts[ci][u, :eidx.size] = 1.0 / eidx.size\n125\t return ids, wts, seen\n126\t\n127\t\n128\tdef build_targets(store: EventStore, vocab_map: np.ndarray, n_catalog: int,\n129\t cutoff: int, horizon: int, seen: list[np.ndarray]):\n130\t \"\"\"Collect new-item organic positives in ``(cutoff, cutoff + horizon]``.\n131\t\n132\t Mirrors the evaluation objective: grade-3 organic likes and grade-1\n133\t organic 80%-completion listens on items the user has not consumed before\n134\t the cutoff.\n135\t \"\"\"\n136\t rows_u, rows_i, rows_w = [], [], []\n137\t for u in range(len(store.users)):\n138\t hi = cutoff + horizon\n139\t got: dict[int, float] = {}\n140\t for name, weight in ((\"strong\", 1.0), (\"like_org\", 2.0)):\n141\t ts, item, starts, ends = store.streams[name]\n142\t s, e = starts[u], ends[u]\n143\t if s == e:\n144\t continue\n145\t a = s + np.searchsorted(ts[s:e], cutoff, \"right\")\n146\t b = s + np.searchsorted(ts[s:e], hi, \"right\")\n147\t if a >= b:\n148\t continue\n149\t idx = _map(vocab_map, item[a:b])\n150\t idx = idx[(idx >= 0) & (idx < n_catalog)]\n151\t for it in np.unique(idx):\n152\t got[int(it)] = max(got.get(int(it), 0.0), weight)\n153\t if not got:\n154\t continue\n155\t prior = seen[u]\n156\t cand = np.fromiter(got.keys(), np.int64, len(got))\n157\t keep = ~np.isin(cand, prior)\n158\t for it in cand[keep]:\n159\t rows_u.append(u)\n160\t rows_i.append(int(it))\n161\t rows_w.append(got[int(it)])\n162\t return (np.asarray(rows_u, np.int64), np.asarray(rows_i, np.int64),\n163\t np.asarray(rows_w, np.float32))\n164\t\n165\t\n166\tdef load_frames(include_val: bool):\n167\t \"\"\"Load listen/like/dislike frames, optionally including the val window.\"\"\"\n168\t splits = [\"train\"] + ([\"val\"] if include_val else [])\n169\t listens, likes, dislikes = [], [], []\n170\t for sp in splits:\n171\t since = du.TRAIN_CUTOFF - 200 * DAY if sp == \"train\" else None\n172\t listens.append(du.load_listens(sp, min_ratio=50, since=since))\n173\t likes.append(du.load_events(\"likes\", sp))\n174\t dislikes.append(du.load_events(\"dislikes\", sp))\n175\t lis = pd.concat(listens, ignore_index=True)\n176\t lik = pd.concat(likes, ignore_index=True)\n177\t dis = pd.concat(dislikes, ignore_index=True)\n178\t strong = lis[(lis.is_organic.values == 1) & (lis.played_ratio_pct.values >= 80)]\n179\t frames = {\n180\t \"listen\": lis[[\"uid\", \"timestamp\", \"item_id\"]],\n181\t \"like\": lik[[\"uid\", \"timestamp\", \"item_id\"]],\n182\t \"dislike\": dis[[\"uid\", \"timestamp\", \"item_id\"]],\n183\t \"strong\": strong[[\"uid\", \"timestamp\", \"item_id\"]],\n184\t \"like_org\": lik[lik.is_organic.values == 1][[\"uid\", \"timestamp\", \"item_id\"]],\n185\t }\n186\t return frames, lis\n187\t\n188\t\n189\tdef build_vocab(listens: pd.DataFrame, catalog: pd.DataFrame, extra: int = 50000):\n190\t \"\"\"Catalog items first, then the most played non-catalog history items.\"\"\"\n\n... [10 lines truncated] ..."
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:36:09.242Z",
"data": {
"type": "total_tokens_reminder",
"text": "14960456 tokens left"
}
}
]
},
{
"id": 11,
"role": "agent",
"timestamp": "2026-08-29T02:36:32.195Z",
"blocks": [
{
"kind": "reasoning",
"timestamp": "2026-08-29T02:36:32.195Z",
"text": ""
},
{
"kind": "tool",
"timestamp": "2026-08-29T02:36:45.306Z",
"callId": "toolu_019rYh3ZL1MxDRwfcgJPApoM",
"name": "Write",
"input": {
"file_path": "/app/solution/model.py",
"content": "\"\"\"Two-tower ranker: a history-based user tower and an item tower.\n\nThe final relevance score is exactly ``dot(user_vector, item_vector)`` with\nboth vectors of dimension ``out_dim``, so item vectors can be precomputed\noffline into a maximum-inner-product index and request-time work is one user\ntower forward pass. The user tower never sees a user id: it reads only pooled\ninteraction history, so new users are served without retraining.\n\"\"\"\nfrom __future__ import annotations\n\nimport torch\nimport torch.nn as nn\nimport torch.nn.functional as F\n\n\nclass ItemTower(nn.Module):\n \"\"\"Map an item id plus its popularity prior to an item vector.\n\n The last output coordinate carries a learned item bias; the user tower\n pins its matching coordinate to 1.0, keeping the score a plain dot product\n of equal-length vectors.\n \"\"\"\n\n def __init__(self, emb: nn.Embedding, n_catalog: int, log_pop: torch.Tensor,\n hidden: int, out_dim: int, dropout: float = 0.1):\n super().__init__()\n self.emb = emb\n self.n_catalog = n_catalog\n self.register_buffer(\"log_pop\", log_pop)\n d = emb.embedding_dim\n self.net = nn.Sequential(\n nn.Linear(d + 1, hidden), nn.GELU(), nn.Dropout(dropout),\n nn.Linear(hidden, out_dim - 1),\n )\n self.bias = nn.Embedding(n_catalog, 1)\n nn.init.zeros_(self.bias.weight)\n\n def forward(self, items: torch.Tensor) -> torch.Tensor:\n e = self.emb(items)\n x = torch.cat([e, self.log_pop[items].unsqueeze(-1)], dim=-1)\n return torch.cat([self.net(x), self.bias(items)], dim=-1)\n\n\nclass UserTower(nn.Module):\n \"\"\"Pool per-channel interaction bags into one user vector.\"\"\"\n\n def __init__(self, emb: nn.Embedding, n_channels: int, hidden: int,\n out_dim: int, dropout: float = 0.1):\n super().__init__()\n self.emb = emb\n self.n_channels = n_channels\n d = emb.embedding_dim\n self.net = nn.Sequential(\n nn.Linear(d * n_channels, hidden), nn.GELU(), nn.Dropout(dropout),\n nn.Linear(hidden, hidden), nn.GELU(),\n nn.Linear(hidden, out_dim - 1),\n )\n\n def forward(self, ids: list[torch.Tensor], wts: list[torch.Tensor]) -> torch.Tensor:\n pooled = []\n for c in range(self.n_channels):\n pooled.append(F.embedding_bag(\n ids[c], self.emb.weight, mode=\"sum\",\n per_sample_weights=wts[c]))\n x = torch.cat(pooled, dim=-1)\n h = self.net(x)\n ones = torch.ones(h.shape[0], 1, dtype=h.dtype, device=h.device)\n return torch.cat([h, ones], dim=-1)\n\n\nclass TwoTower(nn.Module):\n \"\"\"Container holding the shared embedding table and both towers.\"\"\"\n\n def __init__(self, vocab: int, n_catalog: int, log_pop: torch.Tensor,\n dim: int = 64, hidden: int = 256, out_dim: int = 64,\n n_channels: int = 4, dropout: float = 0.1):\n super().__init__()\n self.emb = nn.Embedding(vocab, dim)\n nn.init.normal_(self.emb.weight, std=0.05)\n self.user = UserTower(self.emb, n_channels, hidden, out_dim, dropout)\n self.item = ItemTower(self.emb, n_catalog, log_pop, hidden, out_dim, dropout)\n\n def score(self, u: torch.Tensor, items: torch.Tensor) -> torch.Tensor:\n return u @ self.item(items).t()\n"
},
"result": {
"timestamp": "2026-08-29T02:36:45.314Z",
"content": "File created successfully at: /app/solution/model.py (file state is current in your context — no need to Read it back)",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:36:45.324Z",
"data": {
"type": "total_tokens_reminder",
"text": "14953407 tokens left"
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},
{
"id": 12,
"role": "agent",
"timestamp": "2026-08-29T02:37:18.963Z",
"blocks": [
{
"kind": "tool",
"timestamp": "2026-08-29T02:37:18.963Z",
"callId": "toolu_01Q4H3q44WkBQU8TLqi1nYDp",
"name": "Write",
"input": {
"file_path": "/app/solution/run.py",
"content": "\"\"\"Train the two-tower ranker and emit a ranking for one evaluation stage.\n\nUsage::\n\n python run.py validation solution/validation.parquet\n python run.py test solution/submission.parquet\n\"\"\"\nfrom __future__ import annotations\n\nimport sys\nimport time\nfrom pathlib import Path\n\nimport numpy as np\nimport pandas as pd\nimport torch\nimport torch.nn.functional as F\n\nimport data_utils as du\nimport features as ft\nfrom model import TwoTower\n\ntorch.set_num_threads(8)\nDAY = 86400\nHORIZON = 7 * DAY\nSEED = 17\n\n# Training slice cutoffs, expressed as days before the profile cutoff. Each\n# slice contributes (history-before-cutoff, new organic positives after) pairs.\nSLICE_DAYS = (7, 14, 21, 28, 35, 42, 49, 56)\nEPOCHS = 3\nBATCH = 1024\nN_NEG = 2000\nLR = 3e-3\nDIM = 64\nOUT_DIM = 64\nHIDDEN = 256\n\n\ndef log(msg: str, t0: float) -> None:\n print(f\"[{time.time() - t0:7.1f}s] {msg}\", flush=True)\n\n\ndef to_tensors(ids, wts, rows=None):\n if rows is None:\n return ([torch.from_numpy(a) for a in ids],\n [torch.from_numpy(a) for a in wts])\n return ([torch.from_numpy(a[rows]) for a in ids],\n [torch.from_numpy(a[rows]) for a in wts])\n\n\ndef main() -> None:\n stage = sys.argv[1]\n out_path = Path(sys.argv[2])\n assert stage in (\"validation\", \"test\")\n include_val = stage == \"test\"\n t0 = time.time()\n rng = np.random.default_rng(SEED)\n torch.manual_seed(SEED)\n\n frames, listens = ft.load_frames(include_val)\n log(f\"loaded {len(listens)} positive listens\", t0)\n\n catalog = du.candidate_items()\n vocab, vocab_map, n_catalog = ft.build_vocab(listens, catalog)\n users = np.sort(np.unique(np.concatenate(\n [listens.uid.unique().astype(np.int64), du.target_users()])))\n store = ft.EventStore(frames, users)\n log(f\"vocab={len(vocab)} catalog={n_catalog} users={len(users)}\", t0)\n\n # Popularity prior over the catalog, from the training-history counts.\n counts = np.zeros(n_catalog, np.float64)\n lidx = ft._map(vocab_map, listens.item_id.values)\n keep = (lidx >= 0) & (lidx < n_catalog)\n np.add.at(counts, lidx[keep], 1.0)\n log_pop = torch.from_numpy(\n (np.log1p(counts) - np.log1p(counts).mean()).astype(np.float32))\n # Sampling distribution for shared negatives.\n neg_p = torch.from_numpy((counts + 1.0) ** 0.75)\n neg_p = neg_p / neg_p.sum()\n\n # ---- Training slices -------------------------------------------------\n final_cutoff = du.TRAIN_CUTOFF if stage == \"validation\" else int(\n max(frames[\"listen\"].timestamp.max(), frames[\"like\"].timestamp.max())) + 1\n slice_ids, slice_wts, tu, ti, tw, tslice = [], [], [], [], [], []\n for k, days in enumerate(SLICE_DAYS):\n cutoff = final_cutoff - days * DAY\n ids, wts, seen = ft.build_profiles(store, vocab_map, cutoff)\n u, i, w = ft.build_targets(store, vocab_map, n_catalog, cutoff,\n HORIZON, seen)\n slice_ids.append(ids)\n slice_wts.append(wts)\n tu.append(u)\n ti.append(i)\n tw.append(w)\n tslice.append(np.full(len(u), k, np.int64))\n log(f\"slice -{days}d: {len(u)} pairs\", t0)\n tu = np.concatenate(tu)\n ti = np.concatenate(ti)\n tw = np.concatenate(tw)\n tslice = np.concatenate(tslice)\n log(f\"total training pairs: {len(tu)}\", t0)\n\n slice_t = [to_tensors(slice_ids[k], slice_wts[k])\n for k in range(len(SLICE_DAYS))]\n\n # ---- Model -----------------------------------------------------------\n model = TwoTower(len(vocab), n_catalog, log_pop, dim=DIM, hidden=HIDDEN,\n out_dim=OUT_DIM, n_channels=ft.N_CH)\n opt = torch.optim.AdamW(model.parameters(), lr=LR, weight_decay=1e-5)\n n = len(tu)\n steps_per_epoch = max(1, n // BATCH)\n sched = torch.optim.lr_scheduler.OneCycleLR(\n opt, max_lr=LR, total_steps=EPOCHS * steps_per_epoch, pct_start=0.15)\n log_q = torch.log(neg_p + 1e-12)\n\n ti_t = torch.from_numpy(ti)\n tw_t = torch.from_numpy(tw)\n model.train()\n for epoch in range(EPOCHS):\n perm = rng.permutation(n)\n running, seen_n = 0.0, 0\n for step in range(steps_per_epoch):\n b = perm[step * BATCH:(step + 1) * BATCH]\n pos = ti_t[b]\n negs = torch.multinomial(neg_p, N_NEG, replacement=True)\n cand = torch.cat([pos, negs])\n\n # Group the batch by slice so each user bag uses its own cutoff.\n uvecs = torch.empty(len(b), OUT_DIM)\n sl = tslice[b]\n for k in np.unique(sl):\n m = np.nonzero(sl == k)[0]\n rows = torch.from_numpy(tu[b][m])\n ids_k, wts_k = slice_t[k]\n uvecs[m] = model.user([x[rows] for x in ids_k],\n [x[rows] for x in wts_k])\n\n ivecs = model.item(cand)\n logits = uvecs @ ivecs.t()\n logits[:, len(b):] -= log_q[negs].unsqueeze(0)\n\n # Suppress duplicates of the true positive among the candidates.\n dup = cand.unsqueeze(0) == pos.unsqueeze(1)\n dup[torch.arange(len(b)), torch.arange(len(b))] = False\n logits = logits.masked_fill(dup, -1e9)\n\n target = torch.arange(len(b))\n loss = (F.cross_entropy(logits, target, reduction=\"none\")\n * tw_t[b]).mean()\n opt.zero_grad()\n loss.backward()\n torch.nn.utils.clip_grad_norm_(model.parameters(), 5.0)\n opt.step()\n sched.step()\n running += float(loss) * len(b)\n seen_n += len(b)\n if step % 200 == 0:\n log(f\"epoch {epoch} step {step}/{steps_per_epoch} \"\n f\"loss {running / max(seen_n, 1):.4f}\", t0)\n log(f\"epoch {epoch} done, loss {running / max(seen_n, 1):.4f}\", t0)\n\n # ---- Inference -------------------------------------------------------\n model.eval()\n ids, wts, _ = ft.build_profiles(store, vocab_map, final_cutoff)\n targets = du.target_users()\n rows = np.searchsorted(users, targets)\n eu, eitems, emask = du.eligibility_matrix(stage)\n # Column order of the eligibility matrix, expressed in vocab indices.\n col_vocab = ft._map(vocab_map, eitems)\n assert (col_vocab >= 0).all() and (col_vocab < n_catalog).all()\n col_vocab_t = torch.from_numpy(col_vocab)\n urow = {int(u): r for r, u in enumerate(eu)}\n\n with torch.no_grad():\n item_vecs = torch.cat([model.item(col_vocab_t[s:s + 4096])\n for s in range(0, len(col_vocab), 4096)])\n out_u, out_i, out_r = [], [], []\n for s in range(0, len(targets), 512):\n blk = rows[s:s + 512]\n bt = torch.from_numpy(blk)\n uv = model.user([torch.from_numpy(a)[bt] for a in ids],\n [torch.from_numpy(a)[bt] for a in wts])\n scores = (uv @ item_vecs.t()).numpy()\n for j, uid in enumerate(targets[s:s + 512]):\n m = emask[urow[int(uid)]]\n sc = np.where(m, scores[j], -np.inf)\n top = np.argpartition(-sc, 100)[:100]\n top = top[np.argsort(-sc[top])]\n out_u.append(np.full(100, uid, np.int64))\n out_i.append(eitems[top])\n out_r.append(np.arange(1, 101, dtype=np.int64))\n\n frame = pd.DataFrame({\n \"uid\": np.concatenate(out_u),\n \"item_id\": np.concatenate(out_i),\n \"rank\": np.concatenate(out_r),\n })\n out_path.parent.mkdir(parents=True, exist_ok=True)\n frame.to_parquet(out_path, index=False)\n log(f\"wrote {out_path} ({len(frame)} rows)\", t0)\n\n\nif __name__ == \"__main__\":\n main()\n"
},
"result": {
"timestamp": "2026-08-29T02:37:18.972Z",
"content": "File created successfully at: /app/solution/run.py (file state is current in your context — no need to Read it back)",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:37:18.974Z",
"data": {
"type": "total_tokens_reminder",
"text": "14949887 tokens left"
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]
},
{
"id": 13,
"role": "agent",
"timestamp": "2026-08-29T02:37:26.594Z",
"blocks": [
{
"kind": "reasoning",
"timestamp": "2026-08-29T02:37:26.594Z",
"text": ""
},
{
"kind": "tool",
"timestamp": "2026-08-29T02:37:31.770Z",
"callId": "toolu_01NsZqSPYuaPMRLVAQoeFDXa",
"name": "Edit",
"input": {
"replace_all": false,
"file_path": "/app/solution/run.py",
"old_string": " # Group the batch by slice so each user bag uses its own cutoff.\n uvecs = torch.empty(len(b), OUT_DIM)\n sl = tslice[b]\n for k in np.unique(sl):\n m = np.nonzero(sl == k)[0]\n rows = torch.from_numpy(tu[b][m])\n ids_k, wts_k = slice_t[k]\n uvecs[m] = model.user([x[rows] for x in ids_k],\n [x[rows] for x in wts_k])\n\n ivecs = model.item(cand)\n logits = uvecs @ ivecs.t()\n logits[:, len(b):] -= log_q[negs].unsqueeze(0)",
"new_string": " # Group the batch by slice so each user bag uses its own cutoff.\n sl = tslice[b]\n parts, order = [], []\n for k in np.unique(sl):\n m = np.nonzero(sl == k)[0]\n rows = torch.from_numpy(tu[b][m])\n ids_k, wts_k = slice_t[k]\n parts.append(model.user([x[rows] for x in ids_k],\n [x[rows] for x in wts_k]))\n order.append(m)\n inv = np.empty(len(b), np.int64)\n inv[np.concatenate(order)] = np.arange(len(b))\n uvecs = torch.cat(parts)[torch.from_numpy(inv)]\n\n ivecs = model.item(cand)\n corr = torch.cat([torch.zeros(len(b)), log_q[negs]])\n logits = uvecs @ ivecs.t() - corr.unsqueeze(0)"
},
"result": {
"timestamp": "2026-08-29T02:37:31.780Z",
"content": "The file /app/solution/run.py has been updated successfully. (file state is current in your context — no need to Read it back)",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:37:31.782Z",
"data": {
"type": "total_tokens_reminder",
"text": "14948716 tokens left"
}
}
]
},
{
"id": 14,
"role": "agent",
"timestamp": "2026-08-29T02:37:38.480Z",
"blocks": [
{
"kind": "tool",
"timestamp": "2026-08-29T02:37:38.480Z",
"callId": "toolu_014U7Khs8ZmNSqm6hca1S8ZA",
"name": "Bash",
"input": {
"command": "python -c \"\nimport numpy as np, pandas as pd, data_utils as du\nfor stage,out in [('validation','validation_pop.parquet'),('test','submission.parquet')]:\n eu, eitems, emask = du.eligibility_matrix(stage)\n cat = du.candidate_items().sort_values('popularity_rank')\n rank_of = {int(i):r for r,i in enumerate(cat.item_id.values)}\n score = np.array([-rank_of[int(i)] for i in eitems], dtype=np.float64)\n tg = du.target_users()\n urow={int(u):r for r,u in enumerate(eu)}\n U,I,R=[],[],[]\n for uid in tg:\n m=emask[urow[int(uid)]]\n sc=np.where(m,score,-np.inf)\n top=np.argpartition(-sc,100)[:100]; top=top[np.argsort(-sc[top])]\n U.append(np.full(100,uid)); I.append(eitems[top]); R.append(np.arange(1,101))\n pd.DataFrame({'uid':np.concatenate(U),'item_id':np.concatenate(I),'rank':np.concatenate(R)}).to_parquet(out,index=False)\n print('wrote',out)\n\" && python /task/evaluate_public.py /app/solution/validation_pop.parquet",
"description": "Popularity baseline safety net"
},
"result": {
"timestamp": "2026-08-29T02:37:45.868Z",
"content": "wrote validation_pop.parquet\nwrote submission.parquet\n{\n \"model\": \"/app/solution/validation_pop.parquet\",\n \"scores\": {\n \"quality_ndcg@10\": 0.01071,\n \"quality_users\": 4263\n }\n}",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:37:45.870Z",
"data": {
"type": "total_tokens_reminder",
"text": "14948086 tokens left"
}
}
]
},
{
"id": 15,
"role": "agent",
"timestamp": "2026-08-29T02:37:50.645Z",
"blocks": [
{
"kind": "reasoning",
"timestamp": "2026-08-29T02:37:50.645Z",
"text": ""
},
{
"kind": "tool",
"timestamp": "2026-08-29T02:37:53.526Z",
"callId": "toolu_01HJaTYd5VwnMq1Yc3nbXc7V",
"name": "Bash",
"input": {
"command": "python - <<'EOF'\np='run.py'; s=open(p).read()\ns=s.replace(\"\"\"SLICE_DAYS = (7, 14, 21, 28, 35, 42, 49, 56)\nEPOCHS = 3\"\"\",\"\"\"SLICE_DAYS = tuple(int(x) for x in\n os.environ.get(\"SLICES\", \"7,14,21,28,35,42,49,56\").split(\",\"))\nEPOCHS = int(os.environ.get(\"EPOCHS\", \"3\"))\"\"\")\ns=s.replace(\"import sys\\nimport time\",\"import os\\nimport sys\\nimport time\")\ns=s.replace('STEPCAP_PLACEHOLDER','')\ns=s.replace(\" steps_per_epoch = \",\" steps_per_epoch = \")\nopen(p,'w').write(s)\nEOF\ngrep -n \"SLICE_DAYS\\|EPOCHS =\" run.py",
"description": "Add env overrides"
},
"result": {
"timestamp": "2026-08-29T02:37:53.563Z",
"content": "31:SLICE_DAYS = tuple(int(x) for x in\n33:EPOCHS = int(os.environ.get(\"EPOCHS\", \"3\"))\n88: for k, days in enumerate(SLICE_DAYS):\n107: for k in range(len(SLICE_DAYS))]",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:37:53.566Z",
"data": {
"type": "edited_text_file",
"filename": "/app/solution/run.py",
"snippet": "1\t\"\"\"Train the two-tower ranker and emit a ranking for one evaluation stage.\n2\t\n3\tUsage::\n4\t\n5\t python run.py validation solution/validation.parquet\n6\t python run.py test solution/submission.parquet\n7\t\"\"\"\n8\tfrom __future__ import annotations\n9\t\n10\timport os\n11\timport sys\n12\timport time\n13\tfrom pathlib import Path\n14\t\n15\timport numpy as np\n16\timport pandas as pd\n17\timport torch\n18\timport torch.nn.functional as F\n19\t\n20\timport data_utils as du\n21\timport features as ft\n22\tfrom model import TwoTower\n23\t\n24\ttorch.set_num_threads(8)\n25\tDAY = 86400\n26\tHORIZON = 7 * DAY\n27\tSEED = 17\n28\t\n29\t# Training slice cutoffs, expressed as days before the profile cutoff. Each\n30\t# slice contributes (history-before-cutoff, new organic positives after) pairs.\n31\tSLICE_DAYS = tuple(int(x) for x in\n32\t os.environ.get(\"SLICES\", \"7,14,21,28,35,42,49,56\").split(\",\"))\n33\tEPOCHS = int(os.environ.get(\"EPOCHS\", \"3\"))\n34\tBATCH = 1024\n35\tN_NEG = 2000\n36\tLR = 3e-3\n37\tDIM = 64\n38\tOUT_DIM = 64\n39\tHIDDEN = 256\n40\t\n41\t\n42\tdef log(msg: str, t0: float) -> None:\n43\t print(f\"[{time.time() - t0:7.1f}s] {msg}\", flush=True)\n44\t\n45\t\n46\tdef to_tensors(ids, wts, rows=None):\n47\t if rows is None:\n48\t return ([torch.from_numpy(a) for a in ids],\n49\t [torch.from_numpy(a) for a in wts])\n50\t return ([torch.from_numpy(a[rows]) for a in ids],\n51\t [torch.from_numpy(a[rows]) for a in wts])\n52\t\n53\t\n54\tdef main() -> None:\n55\t stage = sys.argv[1]\n56\t out_path = Path(sys.argv[2])\n57\t assert stage in (\"validation\", \"test\")\n58\t include_val = stage == \"test\"\n59\t t0 = time.time()\n60\t rng = np.random.default_rng(SEED)\n61\t torch.manual_seed(SEED)\n62\t\n63\t frames, listens = ft.load_frames(include_val)\n64\t log(f\"loaded {len(listens)} positive listens\", t0)\n65\t\n66\t catalog = du.candidate_items()\n67\t vocab, vocab_map, n_catalog = ft.build_vocab(listens, catalog)\n68\t users = np.sort(np.unique(np.concatenate(\n69\t [listens.uid.unique().astype(np.int64), du.target_users()])))\n70\t store = ft.EventStore(frames, users)\n71\t log(f\"vocab={len(vocab)} catalog={n_catalog} users={len(users)}\", t0)\n72\t\n73\t # Popularity prior over the catalog, from the training-history counts.\n74\t counts = np.zeros(n_catalog, np.float64)\n75\t lidx = ft._map(vocab_map, listens.item_id.values)\n76\t keep = (lidx >= 0) & (lidx < n_catalog)\n77\t np.add.at(counts, lidx[keep], 1.0)\n78\t log_pop = torch.from_numpy(\n79\t (np.log1p(counts) - np.log1p(counts).mean()).astype(np.float32))\n80\t # Sampling distribution for shared negatives.\n81\t neg_p = torch.from_numpy((counts + 1.0) ** 0.75)\n82\t neg_p = neg_p / neg_p.sum()\n83\t\n84\t # ---- Training slices -------------------------------------------------\n85\t final_cutoff = du.TRAIN_CUTOFF if stage == \"validation\" else int(\n86\t max(frames[\"listen\"].timestamp.max(), frames[\"like\"].timestamp.max())) + 1\n87\t slice_ids, slice_wts, tu, ti, tw, tslice = [], [], [], [], [], []\n88\t for k, days in enumerate(SLICE_DAYS):\n89\t cutoff = final_cutoff - days * DAY\n90\t ids, wts, seen = ft.build_profiles(store, vocab_map, cutoff)\n91\t u, i, w = ft.build_targets(store, vocab_map, n_catalog, cutoff,\n92\t HORIZON, seen)\n93\t slice_ids.append(ids)\n94\t slice_wts.append(wts)\n95\t tu.append(u)\n96\t ti.append(i)\n97\t tw.append(w)\n98\t tslice.append(np.full(len(u), k, np.int64))\n99\t log(f\"slice -{days}d: {len(u)} pairs\", t0)\n100\t tu = np.concatenate(tu)\n101\t ti = np.concatenate(ti)\n102\t tw = np.concatenate(tw)\n103\t tslice = np.concatenate(tslice)\n104\t log(f\"total training pairs: {len(tu)}\", t0)\n105\t\n106\t slice_t = [to_tensors(slice_ids[k], slice_wts[k])\n107\t for k in range(len(SLICE_DAYS))]\n108\t\n109\t # ---- Model -----------------------------------------------------------\n110\t model = TwoTower(len(vocab), n_catalog, log_pop, dim=DIM, hidden=HIDDEN,\n111\t out_dim=OUT_DIM, n_channels=ft.N_CH)\n112\t opt = torch.optim.AdamW(model.parameters(), lr=LR, weight_decay=1e-5)\n113\t n = len(tu)\n114\t steps_per_epoch = max(1, n // BATCH)\n115\t sched = torch.optim.lr_scheduler.OneCycleLR(\n116\t opt, max_lr=LR, total_steps=EPOCHS * steps_per_epoch, pct_start=0.15)\n117\t log_q = torch.log(neg_p + 1e-12)\n118\t\n119\t ti_t = torch.from_numpy(ti)\n120\t tw_t = torch.from_numpy(tw)\n121\t model.train()\n122\t for epoch in range(EPOCHS):\n123\t perm = rng.permutation(n)\n124\t running, seen_n = 0.0, 0\n125\t for step in range(steps_per_epoch):\n126\t b = perm[step * BATCH:(step + 1) * BATCH]\n127\t pos = ti_t[b]\n128\t negs = torch.multinomial(neg_p, N_NEG, replacement=True)\n129\t cand = torch.cat([pos, negs])\n130\t\n131\t # Group the batch by slice so each user bag uses its own cutoff.\n132\t sl = tslice[b]\n133\t parts, order = [], []\n134\t for k in np.unique(sl):\n135\t m = np.nonzero(sl == k)[0]\n136\t rows = torch.from_numpy(tu[b][m])\n137\t ids_k, wts_k = slice_t[k]\n138\t parts.append(model.user([x[rows] for x in ids_k],\n139\t [x[rows] for x in wts_k]))\n140\t order.append(m)\n141\t inv = np.empty(len(b), np.int64)\n142\t inv[np.concatenate(order)] = np.arange(len(b))\n143\t uvecs = torch.cat(parts)[torch.from_numpy(inv)]\n144\t\n145\t ivecs = model.item(cand)\n146\t corr = torch.cat([torch.zeros(len(b)), log_q[negs]])\n147\t logits = uvecs @ ivecs.t() - corr.unsqueeze(0)\n148\t\n149\t # Suppress duplicates of the true positive among the candidates.\n150\t dup = cand.unsqueeze(0) == pos.unsqueeze(1)\n151\t dup[torch.arange(len(b)), torch.arange(len(b))] = False\n152\t logits = logits.masked_fill(dup, -1e9)\n153\t\n154\t target = torch.arange(len(b))\n155\t loss = (F.cross_entropy(logits, target, reduction=\"none\")\n156\t * tw_t[b]).mean()\n157\t opt.zero_grad()\n158\t loss.backward()\n159\t torch.nn.utils.clip_grad_norm_(model.parameters(), 5.0)\n160\t opt.step()\n161\t sched.step()\n162\t running += float(loss) * len(b)\n163\t seen_n += len(b)\n164\t if step % 200 == 0:\n165\t log(f\"epoch {epoch} step {step}/{steps_per_epoch} \"\n166\t f\"loss {running / max(seen_n, 1):.4f}\", t0)\n167\t log(f\"epoch {epoch} done, loss {running / max(seen_n, 1):.4f}\", t0)\n168\t\n169\t # ---- Inference -------------------------------------------------------\n170\t model.eval()\n171\t ids, wts, _ = ft.build_profiles(store, vocab_map, final_cutoff)\n172\t targets = du.target_users()\n173\t rows = np.searchsorted(users, targets)\n174\t eu, eitems, emask = du.eligibility_matrix(stage)\n175\t # Column order of the eligibility matrix, expressed in vocab indices.\n176\t col_vocab = ft._map(vocab_map, eitems)\n177\t assert (col_vocab >= 0).all() and (col_vocab < n_catalog).all()\n178\t col_vocab_t = torch.from_numpy(col_vocab)\n179\t urow = {int(u): r for r, u in enumerate(eu)}\n180\t\n181\t with torch.no_grad():\n182\t item_vecs = torch.cat([model.item(col_vocab_t[s:s + 4096])\n183\t for s in range(0, len(col_vocab), 4096)])\n184\t out_u, out_i, out_r = [], [], []\n185\t for s in range(0, len(targets), 512):\n186\t blk = rows[s:s + 512]\n187\t bt = torch.from_numpy(blk)\n188\t uv = model.user([torch.from_numpy(a)[bt] for a in ids],\n189\t [torch.from_numpy(a)[bt] for a in wts])\n190\t scores = (uv @ item_vecs.t()).numpy()\n191\t for j, uid in enumerate(targets[s:s + 512]):\n192\t m = emask[urow[int(uid)]]\n193\t sc = np.where(m, scores[j], -np.inf)\n194\t top = np.argpartition(-sc, 100)[:100]\n195\t top = top[np.argsort(-sc[top])]\n\n... [16 lines truncated] ..."
}
},
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"timestamp": "2026-08-29T02:37:57.886Z",
"callId": "toolu_014P2G71Heo4SyCyPRFJ4VvX",
"name": "Bash",
"input": {
"command": "SLICES=7 EPOCHS=1 timeout 600 python run.py validation /app/solution/smoke.parquet 2>&1 | tail -30",
"description": "Smoke test training run"
},
"result": {
"timestamp": "2026-08-29T02:38:28.044Z",
"content": "[ 1.4s] loaded 20812310 positive listens\n[ 12.6s] vocab=80000 catalog=30000 users=9135\n[ 15.2s] slice -7d: 50901 pairs\n[ 15.2s] total training pairs: 50901\n/app/solution/run.py:162: UserWarning: Converting a tensor with requires_grad=True to a scalar may lead to unexpected behavior.\nConsider using tensor.detach() first. (Triggered internally at /pytorch/torch/csrc/autograd/generated/python_variable_methods.cpp:835.)\n running += float(loss) * len(b)\n[ 18.1s] epoch 0 step 0/49 loss 20.1558\n[ 22.6s] epoch 0 done, loss 19.3905\n[ 26.0s] wrote /app/solution/smoke.parquet (845600 rows)",
"isError": false
}
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"callId": "toolu_016iw6UiUJRhC6Vmmkgdon7c",
"name": "Bash",
"input": {
"command": "python /task/evaluate_public.py /app/solution/smoke.parquet",
"description": "Score smoke run"
},
"result": {
"timestamp": "2026-08-29T02:38:35.243Z",
"content": "{\n \"model\": \"/app/solution/smoke.parquet\",\n \"scores\": {\n \"quality_ndcg@10\": 0.029194,\n \"quality_users\": 4263\n }\n}",
"isError": false
}
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"callId": "toolu_01JYLihjSW5Y1tbw939Gm9M4",
"name": "Bash",
"input": {
"command": "EPOCHS=6 timeout 1200 python run.py validation /app/solution/validation.parquet 2>&1 | grep -v UserWarning | grep -v \"Consider using\" | grep -v \"running +=\" | tail -30 && python /task/evaluate_public.py /app/solution/validation.parquet",
"description": "Full validation training run"
},
"result": {
"timestamp": "2026-08-29T02:40:40.221Z",
"content": "Command did not complete within its 120s timeout and was moved to the background (ID: bah2z5a7c). Output is being written to: /tmp/claude-1000/-app/53bed668-7041-4440-8306-d01153e497d0/tasks/bah2z5a7c.output. You will be notified when it completes. To check interim output, use Read on that file path.",
"isError": false
}
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"name": "Bash",
"input": {
"command": "sleep 100; tail -5 /tmp/claude-1000/-app/53bed668-7041-4440-8306-d01153e497d0/tasks/bah2z5a7c.output",
"description": "Check run progress"
},
"result": {
"timestamp": "2026-08-29T02:42:37.641Z",
"content": "(Bash completed with no output)",
"isError": false
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"name": "Bash",
"input": {
"command": "grep -v Warning /tmp/claude-1000/-app/53bed668-7041-4440-8306-d01153e497d0/tasks/bah2z5a7c.output | tail -12",
"description": "Check run output"
},
"result": {
"timestamp": "2026-08-29T02:42:39.886Z",
"content": "(Bash completed with no output)",
"isError": false
}
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{
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{
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"blocks": [
{
"kind": "tool",
"timestamp": "2026-08-29T02:42:42.747Z",
"callId": "toolu_018WdBwKEP5vGt8PssGyFF7H",
"name": "Bash",
"input": {
"command": "ls -la /tmp/claude-1000/-app/53bed668-7041-4440-8306-d01153e497d0/tasks/ 2>/dev/null; cat /tmp/claude-1000/-app/53bed668-7041-4440-8306-d01153e497d0/tasks/bah2z5a7c.output 2>/dev/null | tail -20",
"description": "Inspect task output file"
},
"result": {
"timestamp": "2026-08-29T02:42:42.778Z",
"content": "total 8\ndrwxr-xr-x 2 agent agent 4096 Aug 29 02:42 .\ndrwxr-xr-x 3 agent agent 4096 Aug 29 02:33 ..\n-rw-r--r-- 1 agent agent 0 Aug 29 02:38 bah2z5a7c.output\n-rw-r--r-- 1 agent agent 0 Aug 29 02:42 btw6oi7fu.output",
"isError": false
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},
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"kind": "tool",
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"callId": "toolu_01ASRpxdVrujXgMsmevfCDZ3",
"name": "Bash",
"input": {
"command": "cat >> features.py <<'EOF'\n\n\nclass PopStats:\n \"\"\"Time-sorted catalog event streams for cutoff-correct item priors.\"\"\"\n\n def __init__(self, frames: dict[str, pd.DataFrame], vocab_map: np.ndarray,\n n_catalog: int):\n self.n_catalog = n_catalog\n self.streams = {}\n for name in (\"listen\", \"strong\", \"like_org\"):\n df = frames[name]\n idx = _map(vocab_map, df.item_id.values)\n ts = df.timestamp.values.astype(np.int64)\n keep = (idx >= 0) & (idx < n_catalog)\n idx, ts = idx[keep], ts[keep]\n o = np.argsort(ts, kind=\"stable\")\n self.streams[name] = (ts[o], idx[o])\n\n def _count(self, name: str, lo: int | None, hi: int) -> np.ndarray:\n ts, idx = self.streams[name]\n b = np.searchsorted(ts, hi, \"left\")\n a = 0 if lo is None else np.searchsorted(ts, lo, \"left\")\n return np.bincount(idx[a:b], minlength=self.n_catalog).astype(np.float32)\n\n def features(self, cutoff: int) -> np.ndarray:\n \"\"\"Return standardized log-popularity features as of ``cutoff``.\"\"\"\n d = DAY\n p7 = self._count(\"listen\", cutoff - 7 * d, cutoff)\n p28 = self._count(\"listen\", cutoff - 28 * d, cutoff)\n pall = self._count(\"listen\", None, cutoff)\n s28 = self._count(\"strong\", cutoff - 28 * d, cutoff)\n l28 = self._count(\"like_org\", cutoff - 28 * d, cutoff)\n cols = [np.log1p(p7), np.log1p(p28), np.log1p(pall),\n np.log1p(s28), np.log1p(l28),\n np.log1p(p7) - np.log1p(p28 / 4.0)]\n f = np.stack(cols, axis=1).astype(np.float32)\n f -= f.mean(0, keepdims=True)\n f /= (f.std(0, keepdims=True) + 1e-6)\n return f\n\n\nN_POP_FEATS = 6\nEOF\npython -c \"import features; print(features.N_POP_FEATS)\"",
"description": "Add cutoff-correct item popularity features"
},
"result": {
"timestamp": "2026-08-29T02:42:59.996Z",
"content": "6",
"isError": false
}
},
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"timestamp": "2026-08-29T02:43:11.015Z",
"blocks": [
{
"kind": "tool",
"timestamp": "2026-08-29T02:43:11.015Z",
"callId": "toolu_011Uj814BAYwgtqrpByG2hd4",
"name": "Bash",
"input": {
"command": "python - <<'EOF'\np='model.py'; s=open(p).read()\ns=s.replace(''' def __init__(self, emb: nn.Embedding, n_catalog: int, log_pop: torch.Tensor,\n hidden: int, out_dim: int, dropout: float = 0.1):\n super().__init__()\n self.emb = emb\n self.n_catalog = n_catalog\n self.register_buffer(\"log_pop\", log_pop)\n d = emb.embedding_dim\n self.net = nn.Sequential(\n nn.Linear(d + 1, hidden), nn.GELU(), nn.Dropout(dropout),\n nn.Linear(hidden, out_dim - 1),\n )\n self.bias = nn.Embedding(n_catalog, 1)\n nn.init.zeros_(self.bias.weight)\n\n def forward(self, items: torch.Tensor) -> torch.Tensor:\n e = self.emb(items)\n x = torch.cat([e, self.log_pop[items].unsqueeze(-1)], dim=-1)\n return torch.cat([self.net(x), self.bias(items)], dim=-1)''',''' def __init__(self, emb: nn.Embedding, n_catalog: int, n_feats: int,\n hidden: int, out_dim: int, dropout: float = 0.1):\n super().__init__()\n self.emb = emb\n self.n_catalog = n_catalog\n d = emb.embedding_dim\n self.net = nn.Sequential(\n nn.Linear(d + n_feats, hidden), nn.GELU(), nn.Dropout(dropout),\n nn.Linear(hidden, out_dim - 1),\n )\n self.bias = nn.Sequential(\n nn.Linear(d + n_feats, 64), nn.GELU(), nn.Linear(64, 1))\n\n def forward(self, items: torch.Tensor, feats: torch.Tensor) -> torch.Tensor:\n x = torch.cat([self.emb(items), feats], dim=-1)\n return torch.cat([self.net(x), self.bias(x)], dim=-1)''')\ns=s.replace(''' def __init__(self, vocab: int, n_catalog: int, log_pop: torch.Tensor,\n dim: int = 64, hidden: int = 256, out_dim: int = 64,\n n_channels: int = 4, dropout: float = 0.1):''',''' def __init__(self, vocab: int, n_catalog: int, n_feats: int,\n dim: int = 64, hidden: int = 256, out_dim: int = 64,\n n_channels: int = 4, dropout: float = 0.1):''')\ns=s.replace('self.item = ItemTower(self.emb, n_catalog, log_pop, hidden, out_dim, dropout)',\n 'self.item = ItemTower(self.emb, n_catalog, n_feats, hidden, out_dim, dropout)')\ns=s.replace(''' def score(self, u: torch.Tensor, items: torch.Tensor) -> torch.Tensor:\n return u @ self.item(items).t()''',''' def score(self, u: torch.Tensor, items: torch.Tensor,\n feats: torch.Tensor) -> torch.Tensor:\n return u @ self.item(items, feats).t()''')\nopen(p,'w').write(s)\nEOF\npython -c \"import model; print('ok')\"",
"description": "Update item tower for popularity features"
},
"result": {
"timestamp": "2026-08-29T02:43:15.695Z",
"content": "ok",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:43:15.699Z",
"data": {
"type": "edited_text_file",
"filename": "/app/solution/model.py",
"snippet": "16\tclass ItemTower(nn.Module):\n17\t \"\"\"Map an item id plus its popularity prior to an item vector.\n18\t\n19\t The last output coordinate carries a learned item bias; the user tower\n20\t pins its matching coordinate to 1.0, keeping the score a plain dot product\n21\t of equal-length vectors.\n22\t \"\"\"\n23\t\n24\t def __init__(self, emb: nn.Embedding, n_catalog: int, n_feats: int,\n25\t hidden: int, out_dim: int, dropout: float = 0.1):\n26\t super().__init__()\n27\t self.emb = emb\n28\t self.n_catalog = n_catalog\n29\t d = emb.embedding_dim\n30\t self.net = nn.Sequential(\n31\t nn.Linear(d + n_feats, hidden), nn.GELU(), nn.Dropout(dropout),\n32\t nn.Linear(hidden, out_dim - 1),\n33\t )\n34\t self.bias = nn.Sequential(\n35\t nn.Linear(d + n_feats, 64), nn.GELU(), nn.Linear(64, 1))\n36\t\n37\t def forward(self, items: torch.Tensor, feats: torch.Tensor) -> torch.Tensor:\n38\t x = torch.cat([self.emb(items), feats], dim=-1)\n39\t return torch.cat([self.net(x), self.bias(x)], dim=-1)\n40\t\n41\t\n42\tclass UserTower(nn.Module):\n43\t \"\"\"Pool per-channel interaction bags into one user vector.\"\"\"\n44\t\n45\t def __init__(self, emb: nn.Embedding, n_channels: int, hidden: int,\n46\t out_dim: int, dropout: float = 0.1):\n47\t super().__init__()\n...\n66\t h = self.net(x)\n67\t ones = torch.ones(h.shape[0], 1, dtype=h.dtype, device=h.device)\n68\t return torch.cat([h, ones], dim=-1)\n69\t\n70\t\n71\tclass TwoTower(nn.Module):\n72\t \"\"\"Container holding the shared embedding table and both towers.\"\"\"\n73\t\n74\t def __init__(self, vocab: int, n_catalog: int, n_feats: int,\n75\t dim: int = 64, hidden: int = 256, out_dim: int = 64,\n76\t n_channels: int = 4, dropout: float = 0.1):\n77\t super().__init__()\n78\t self.emb = nn.Embedding(vocab, dim)\n79\t nn.init.normal_(self.emb.weight, std=0.05)\n80\t self.user = UserTower(self.emb, n_channels, hidden, out_dim, dropout)\n81\t self.item = ItemTower(self.emb, n_catalog, n_feats, hidden, out_dim, dropout)\n82\t\n83\t def score(self, u: torch.Tensor, items: torch.Tensor,\n84\t feats: torch.Tensor) -> torch.Tensor:\n85\t return u @ self.item(items, feats).t()"
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:43:15.699Z",
"data": {
"type": "total_tokens_reminder",
"text": "14937791 tokens left"
}
}
]
},
{
"id": 24,
"role": "agent",
"timestamp": "2026-08-29T02:43:17.524Z",
"blocks": [
{
"kind": "message",
"timestamp": "2026-08-29T02:43:17.524Z",
"text": "Now updating the training loop for per-slice batching with cutoff-correct item features."
},
{
"kind": "tool",
"timestamp": "2026-08-29T02:43:37.162Z",
"callId": "toolu_01MToKDCBDrwuBkagFMUfPrp",
"name": "Bash",
"input": {
"command": "python - <<'EOF'\np='run.py'; s=open(p).read()\n\ns=s.replace(''' # Popularity prior over the catalog, from the training-history counts.\n counts = np.zeros(n_catalog, np.float64)\n lidx = ft._map(vocab_map, listens.item_id.values)\n keep = (lidx >= 0) & (lidx < n_catalog)\n np.add.at(counts, lidx[keep], 1.0)\n log_pop = torch.from_numpy(\n (np.log1p(counts) - np.log1p(counts).mean()).astype(np.float32))\n # Sampling distribution for shared negatives.\n neg_p = torch.from_numpy((counts + 1.0) ** 0.75)\n neg_p = neg_p / neg_p.sum()\n''',''' pop = ft.PopStats(frames, vocab_map, n_catalog)\n counts = np.zeros(n_catalog, np.float64)\n lidx = ft._map(vocab_map, listens.item_id.values)\n keep = (lidx >= 0) & (lidx < n_catalog)\n np.add.at(counts, lidx[keep], 1.0)\n # Sampling distribution for shared negatives.\n neg_p = torch.from_numpy((counts + 1.0) ** 0.75)\n neg_p = neg_p / neg_p.sum()\n''')\n\ns=s.replace(''' slice_ids, slice_wts, tu, ti, tw, tslice = [], [], [], [], [], []\n for k, days in enumerate(SLICE_DAYS):\n cutoff = final_cutoff - days * DAY\n ids, wts, seen = ft.build_profiles(store, vocab_map, cutoff)\n u, i, w = ft.build_targets(store, vocab_map, n_catalog, cutoff,\n HORIZON, seen)\n slice_ids.append(ids)''',''' slice_ids, slice_wts, tu, ti, tw, tslice = [], [], [], [], [], []\n slice_feats = []\n for k, days in enumerate(SLICE_DAYS):\n cutoff = final_cutoff - days * DAY\n ids, wts, seen = ft.build_profiles(store, vocab_map, cutoff)\n u, i, w = ft.build_targets(store, vocab_map, n_catalog, cutoff,\n HORIZON, seen)\n slice_feats.append(torch.from_numpy(pop.features(cutoff)))\n slice_ids.append(ids)''')\n\nold_loop = s[s.index(' ti_t = torch.from_numpy(ti)'):s.index(' # ---- Inference')]\nnew_loop = ''' ti_t = torch.from_numpy(ti)\n tw_t = torch.from_numpy(tw)\n slice_rows = [np.nonzero(tslice == k)[0] for k in range(len(SLICE_DAYS))]\n model.train()\n for epoch in range(EPOCHS):\n # Batches are drawn within a slice so every candidate item shares one\n # cutoff-correct popularity feature vector.\n batches = []\n for k, rows_k in enumerate(slice_rows):\n perm = rng.permutation(rows_k)\n for s0 in range(0, len(perm) - BATCH + 1, BATCH):\n batches.append((k, perm[s0:s0 + BATCH]))\n rng.shuffle(batches)\n running, seen_n = 0.0, 0\n for step, (k, b) in enumerate(batches):\n pos = ti_t[b]\n negs = torch.multinomial(neg_p, N_NEG, replacement=True)\n cand = torch.cat([pos, negs])\n feats = slice_feats[k][cand]\n\n rows = torch.from_numpy(tu[b])\n ids_k, wts_k = slice_t[k]\n uvecs = model.user([x[rows] for x in ids_k],\n [x[rows] for x in wts_k])\n\n ivecs = model.item(cand, feats)\n corr = torch.cat([torch.zeros(len(b)), log_q[negs]])\n logits = uvecs @ ivecs.t() - corr.unsqueeze(0)\n\n # Suppress duplicates of the true positive among the candidates.\n dup = cand.unsqueeze(0) == pos.unsqueeze(1)\n dup[torch.arange(len(b)), torch.arange(len(b))] = False\n logits = logits.masked_fill(dup, -1e9)\n\n target = torch.arange(len(b))\n loss = (F.cross_entropy(logits, target, reduction=\"none\")\n * tw_t[b]).mean()\n opt.zero_grad()\n loss.backward()\n torch.nn.utils.clip_grad_norm_(model.parameters(), 5.0)\n opt.step()\n sched.step()\n running += float(loss.detach()) * len(b)\n seen_n += len(b)\n if step % 300 == 0:\n log(f\"epoch {epoch} step {step}/{len(batches)} \"\n f\"loss {running / max(seen_n, 1):.4f}\", t0)\n log(f\"epoch {epoch} done, loss {running / max(seen_n, 1):.4f}\", t0)\n\n'''\ns = s.replace(old_loop, new_loop)\n\ns=s.replace(''' model = TwoTower(len(vocab), n_catalog, log_pop, dim=DIM, hidden=HIDDEN,''',\n ''' model = TwoTower(len(vocab), n_catalog, ft.N_POP_FEATS, dim=DIM, hidden=HIDDEN,''')\ns=s.replace(''' n = len(tu)\n steps_per_epoch = max(1, n // BATCH)''',''' steps_per_epoch = max(1, sum(int((tslice == k).sum()) // BATCH\n for k in range(len(SLICE_DAYS))))''')\n\ns=s.replace(''' item_vecs = torch.cat([model.item(col_vocab_t[s:s + 4096])\n for s in range(0, len(col_vocab), 4096)])''',\n''' final_feats = torch.from_numpy(pop.features(final_cutoff))\n item_vecs = torch.cat([\n model.item(col_vocab_t[s:s + 4096], final_feats[col_vocab_t[s:s + 4096]])\n for s in range(0, len(col_vocab), 4096)])''')\nopen(p,'w').write(s)\nEOF\npython -c \"import ast;ast.parse(open('run.py').read());print('ok')\" && grep -n \"log_pop\\|steps_per_epoch\\|slice_feats\" run.py",
"description": "Rewrite training loop for per-slice batches"
},
"result": {
"timestamp": "2026-08-29T02:43:37.437Z",
"content": "ok\n86: slice_feats = []\n92: slice_feats.append(torch.from_numpy(pop.features(cutoff)))\n113: steps_per_epoch = max(1, sum(int((tslice == k).sum()) // BATCH\n116: opt, max_lr=LR, total_steps=EPOCHS * steps_per_epoch, pct_start=0.15)\n137: feats = slice_feats[k][cand]",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:43:37.441Z",
"data": {
"type": "total_tokens_reminder",
"text": "14934233 tokens left"
}
}
]
},
{
"id": 25,
"role": "agent",
"timestamp": "2026-08-29T02:43:40.949Z",
"blocks": [
{
"kind": "tool",
"timestamp": "2026-08-29T02:43:40.949Z",
"callId": "toolu_01TGKwCwjZvEkbmqGhYxKEdy",
"name": "Bash",
"input": {
"command": "cat /tmp/claude-1000/-app/53bed668-7041-4440-8306-d01153e497d0/tasks/bah2z5a7c.output; ls -la /app/solution/",
"description": "Check v1 run status"
},
"result": {
"timestamp": "2026-08-29T02:43:41.024Z",
"content": "total 2196\ndrwxr-xr-x 1 agent agent 4096 Aug 29 02:38 .\ndrwxr-xr-x 1 agent agent 4096 Aug 29 02:29 ..\n-rw-r--r-- 1 agent agent 1930 Aug 29 02:34 data_utils.py\n-rw-r--r-- 1 agent agent 9712 Aug 29 02:42 features.py\n-rw-r--r-- 1 agent agent 3326 Aug 29 02:43 model.py\n-rw-r--r-- 1 agent agent 8132 Aug 29 02:43 run.py\n-rw-r--r-- 1 agent agent 738378 Aug 29 02:38 smoke.parquet\n-rw-r--r-- 1 agent agent 735840 Aug 29 02:37 submission.parquet\n-rw-r--r-- 1 agent agent 728599 Aug 29 02:37 validation_pop.parquet",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:43:41.035Z",
"data": {
"type": "total_tokens_reminder",
"text": "14933923 tokens left"
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]
},
{
"id": 26,
"role": "agent",
"timestamp": "2026-08-29T02:43:48.456Z",
"blocks": [
{
"kind": "reasoning",
"timestamp": "2026-08-29T02:43:48.456Z",
"text": ""
},
{
"kind": "tool",
"timestamp": "2026-08-29T02:43:48.601Z",
"callId": "toolu_017r1QKHNU9hmVCHSLHANRFe",
"name": "Bash",
"input": {
"command": "ps aux | grep -c \"[r]un.py\"; sleep 60; ls -la /app/solution/*.parquet",
"description": "Wait for v1 run"
},
"result": {
"timestamp": "2026-08-29T02:44:48.700Z",
"content": "6\n-rw-r--r-- 1 agent agent 738378 Aug 29 02:38 /app/solution/smoke.parquet\n-rw-r--r-- 1 agent agent 735840 Aug 29 02:37 /app/solution/submission.parquet\n-rw-r--r-- 1 agent agent 728599 Aug 29 02:37 /app/solution/validation_pop.parquet",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:44:48.708Z",
"data": {
"type": "total_tokens_reminder",
"text": "14933086 tokens left"
}
}
]
},
{
"id": 27,
"role": "agent",
"timestamp": "2026-08-29T02:44:51.284Z",
"blocks": [
{
"kind": "tool",
"timestamp": "2026-08-29T02:44:51.284Z",
"callId": "toolu_01XQWUMRdEsxA7E96YMAB5zQ",
"name": "Bash",
"input": {
"command": "sleep 90; ls -la /app/solution/validation.parquet 2>/dev/null && python /task/evaluate_public.py /app/solution/validation.parquet || echo \"still running\"",
"description": "Check v1 result"
},
"result": {
"timestamp": "2026-08-29T02:46:24.725Z",
"content": "-rw-r--r-- 1 agent agent 1662857 Aug 29 02:45 /app/solution/validation.parquet\n{\n \"model\": \"/app/solution/validation.parquet\",\n \"scores\": {\n \"quality_ndcg@10\": 0.022765,\n \"quality_users\": 4263\n }\n}",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:45:16.675Z",
"data": {
"type": "queued_command",
"prompt": "\nbah2z5a7c\ntoolu_01JYLihjSW5Y1tbw939Gm9M4\n/tmp/claude-1000/-app/53bed668-7041-4440-8306-d01153e497d0/tasks/bah2z5a7c.output\ncompleted\nBackground command \"Full validation training run\" completed (exit code 0)\n",
"commandMode": "task-notification",
"timestamp": "2026-08-29T02:45:16.675Z"
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:46:24.727Z",
"data": {
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"text": "14932789 tokens left"
}
}
]
},
{
"id": 28,
"role": "agent",
"timestamp": "2026-08-29T02:46:34.350Z",
"blocks": [
{
"kind": "reasoning",
"timestamp": "2026-08-29T02:46:34.350Z",
"text": ""
},
{
"kind": "tool",
"timestamp": "2026-08-29T02:46:43.184Z",
"callId": "toolu_019pLdsPMh7yufZVk2FyNNK3",
"name": "Bash",
"input": {
"command": "python - <<'EOF'\np='run.py'; s=open(p).read()\n\n# factor inference into a function\nold = s[s.index(' # ---- Inference'):]\nnew = ''' # ---- Inference -------------------------------------------------------\n _, path = rank_and_write(model, store, vocab_map, pop, final_cutoff, stage,\n users, out_path)\n log(f\"wrote {path}\", t0)\n\n\ndef rank_and_write(model, store, vocab_map, pop, final_cutoff, stage, users,\n out_path):\n \"\"\"Score every eligible candidate and write the top-100 ranking.\"\"\"\n model.eval()\n ids, wts, _ = ft.build_profiles(store, vocab_map, final_cutoff)\n targets = du.target_users()\n rows = np.searchsorted(users, targets)\n eu, eitems, emask = du.eligibility_matrix(stage)\n col_vocab = ft._map(vocab_map, eitems)\n col_vocab_t = torch.from_numpy(col_vocab)\n urow = {int(u): r for r, u in enumerate(eu)}\n\n with torch.no_grad():\n feats = torch.from_numpy(pop.features(final_cutoff))\n item_vecs = torch.cat([\n model.item(col_vocab_t[s:s + 4096], feats[col_vocab_t[s:s + 4096]])\n for s in range(0, len(col_vocab), 4096)])\n out_u, out_i, out_r = [], [], []\n for s in range(0, len(targets), 512):\n bt = torch.from_numpy(rows[s:s + 512])\n uv = model.user([torch.from_numpy(a)[bt] for a in ids],\n [torch.from_numpy(a)[bt] for a in wts])\n scores = (uv @ item_vecs.t()).numpy()\n for j, uid in enumerate(targets[s:s + 512]):\n sc = np.where(emask[urow[int(uid)]], scores[j], -np.inf)\n top = np.argpartition(-sc, 100)[:100]\n top = top[np.argsort(-sc[top])]\n out_u.append(np.full(100, uid, np.int64))\n out_i.append(eitems[top].astype(np.int64))\n out_r.append(np.arange(1, 101, dtype=np.int64))\n frame = pd.DataFrame({\n \"uid\": np.concatenate(out_u),\n \"item_id\": np.concatenate(out_i),\n \"rank\": np.concatenate(out_r),\n })\n out_path.parent.mkdir(parents=True, exist_ok=True)\n frame.to_parquet(out_path, index=False)\n model.train()\n return frame, out_path\n\n\nif __name__ == \"__main__\":\n main()\n'''\ns = s[:s.index(' # ---- Inference')] + new\nopen(p,'w').write(s)\nEOF\npython -c \"import ast;ast.parse(open('run.py').read());print('ok')\"; tail -5 run.py",
"description": "Refactor inference into a function"
},
"result": {
"timestamp": "2026-08-29T02:46:43.302Z",
"content": "ok\n return frame, out_path\n\n\nif __name__ == \"__main__\":\n main()",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:46:43.304Z",
"data": {
"type": "total_tokens_reminder",
"text": "14930735 tokens left"
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}
]
},
{
"id": 29,
"role": "agent",
"timestamp": "2026-08-29T02:46:50.377Z",
"blocks": [
{
"kind": "tool",
"timestamp": "2026-08-29T02:46:50.377Z",
"callId": "toolu_01Uy1WiEnCL3Cou94Cj5KbbA",
"name": "Bash",
"input": {
"command": "python - <<'EOF'\np='run.py'; s=open(p).read()\ns=s.replace(''' log(f\"epoch {epoch} done, loss {running / max(seen_n, 1):.4f}\", t0)\n''',''' log(f\"epoch {epoch} done, loss {running / max(seen_n, 1):.4f}\", t0)\n if stage == \"validation\":\n ep_path = out_path.with_name(f\"{out_path.stem}_ep{epoch}.parquet\")\n rank_and_write(model, store, vocab_map, pop, final_cutoff, stage,\n users, ep_path)\n log(f\"epoch {epoch} val ndcg@10 = {score_public(ep_path):.5f}\", t0)\n''')\ns=s.replace('''def log(msg: str, t0: float) -> None:''','''def score_public(path: Path) -> float:\n \"\"\"Score a validation ranking with the public evaluator.\"\"\"\n sys.path.insert(0, \"/task\")\n import evaluate_public as ev\n targets = set(pd.read_parquet(\"/task/data/target_users.parquet\").uid.astype(int))\n if not hasattr(score_public, \"_truth\"):\n elig = ev.CandidateSet(Path(\"/task/data/validation_eligible_candidates.npz\"))\n score_public._truth = (elig, ev.validation_truth(elig, targets))\n elig, truth = score_public._truth\n ranked = ev.load_submission(path, elig, targets)\n return float(ev.score(ranked, truth)[\"quality_ndcg@10\"])\n\n\ndef log(msg: str, t0: float) -> None:''')\nopen(p,'w').write(s)\nEOF\npython -c \"import ast;ast.parse(open('run.py').read());print('ok')\"",
"description": "Add per-epoch validation scoring"
},
"result": {
"timestamp": "2026-08-29T02:46:50.493Z",
"content": "ok",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:46:50.495Z",
"data": {
"type": "total_tokens_reminder",
"text": "14930010 tokens left"
}
}
]
},
{
"id": 30,
"role": "agent",
"timestamp": "2026-08-29T02:46:53.852Z",
"blocks": [
{
"kind": "tool",
"timestamp": "2026-08-29T02:46:53.852Z",
"callId": "toolu_01Wzkvo9Xjk4XfmZtV9agkDe",
"name": "Bash",
"input": {
"command": "(SLICES=7,14,21,28 EPOCHS=4 python run.py validation /app/solution/v2.parquet > /app/solution/v2.log 2>&1; echo DONE >> /app/solution/v2.log) &\nsleep 115; grep -E \"slice|epoch .* val|loaded|vocab\" /app/solution/v2.log | tail -20",
"description": "Run v2 with per-epoch validation"
},
"result": {
"timestamp": "2026-08-29T02:48:48.897Z",
"content": "[ 1.4s] loaded 20812310 positive listens\n[ 12.2s] vocab=80000 catalog=30000 users=9135\n[ 16.6s] slice -7d: 50901 pairs\n[ 19.0s] slice -14d: 50095 pairs\n[ 21.3s] slice -21d: 49094 pairs\n[ 23.5s] slice -28d: 47485 pairs\n[ 49.5s] epoch 0 val ndcg@10 = 0.02795\n[ 72.2s] epoch 1 val ndcg@10 = 0.02545\n[ 95.4s] epoch 2 val ndcg@10 = 0.02466",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:48:48.899Z",
"data": {
"type": "total_tokens_reminder",
"text": "14929770 tokens left"
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}
]
},
{
"id": 31,
"role": "agent",
"timestamp": "2026-08-29T02:49:03.740Z",
"blocks": [
{
"kind": "reasoning",
"timestamp": "2026-08-29T02:49:03.740Z",
"text": ""
},
{
"kind": "tool",
"timestamp": "2026-08-29T02:49:07.690Z",
"callId": "toolu_01KTuFBhANfhyPkGYzjQXMYP",
"name": "Bash",
"input": {
"command": "python - <<'EOF'\np='run.py'; s=open(p).read()\ns=s.replace('LR = 3e-3\\nDIM = 64\\nOUT_DIM = 64\\nHIDDEN = 256',\n 'LR = float(os.environ.get(\"LR\", \"3e-3\"))\\nDIM = int(os.environ.get(\"DIM\", \"64\"))\\nOUT_DIM = int(os.environ.get(\"OUT_DIM\", \"64\"))\\nHIDDEN = int(os.environ.get(\"HIDDEN\", \"256\"))\\nDROPOUT = float(os.environ.get(\"DROPOUT\", \"0.1\"))\\nWD = float(os.environ.get(\"WD\", \"1e-5\"))\\nN_NEG = int(os.environ.get(\"NNEG\", \"2000\"))')\ns=s.replace('N_NEG = 2000\\n','')\ns=s.replace('out_dim=OUT_DIM, n_channels=ft.N_CH)','out_dim=OUT_DIM, n_channels=ft.N_CH, dropout=DROPOUT)')\ns=s.replace('weight_decay=1e-5)','weight_decay=WD)')\nopen(p,'w').write(s)\nEOF\ngrep -n \"^LR\\|^DIM\\|^DROPOUT\\|^WD\\|^N_NEG\\|dropout=DROPOUT\\|weight_decay\" run.py",
"description": "Add hyperparameter env overrides"
},
"result": {
"timestamp": "2026-08-29T02:49:07.725Z",
"content": "35:LR = float(os.environ.get(\"LR\", \"3e-3\"))\n36:DIM = int(os.environ.get(\"DIM\", \"64\"))\n39:DROPOUT = float(os.environ.get(\"DROPOUT\", \"0.1\"))\n40:WD = float(os.environ.get(\"WD\", \"1e-5\"))\n41:N_NEG = int(os.environ.get(\"NNEG\", \"2000\"))\n126: out_dim=OUT_DIM, n_channels=ft.N_CH, dropout=DROPOUT)\n127: opt = torch.optim.AdamW(model.parameters(), lr=LR, weight_decay=WD)",
"isError": false
}
},
{
"kind": "context",
"timestamp": "2026-08-29T02:49:07.727Z",
"data": {
"type": "total_tokens_reminder",
"text": "14928096 tokens left"
}
}
]
},
{
"id": 32,
"role": "agent",
"timestamp": "2026-08-29T02:49:11.395Z",
"blocks": [
{
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"description": "Regularized 8-slice run"
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"timestamp": "2026-08-29T02:51:01.445Z",
"content": "[ 79.6s] epoch 0 val ndcg@10 = 0.02662",
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"command": "sleep 105; grep -E \"epoch .* val|DONE\" /app/solution/v3.log | tail",
"description": "Check v3 epochs"
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"timestamp": "2026-08-29T02:52:51.080Z",
"content": "[ 79.6s] epoch 0 val ndcg@10 = 0.02662\n[ 123.5s] epoch 1 val ndcg@10 = 0.02213\n[ 167.3s] epoch 2 val ndcg@10 = 0.02148\nDONE",
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"command": "(SLICES=7,14,21,28 EPOCHS=1 NNEG=3000 python run.py validation /app/solution/v4.parquet > v4.log 2>&1; echo DONE >> v4.log) & sleep 105; grep -E \"epoch .* val|DONE|wrote\" /app/solution/v4.log",
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"timestamp": "2026-08-29T02:54:45.658Z",
"content": "[1]+ Done ( SLICES=7,14,21,28 EPOCHS=1 NNEG=3000 python run.py validation /app/solution/v4.parquet > v4.log 2>&1; echo DONE >> v4.log )\n[ 53.6s] epoch 0 val ndcg@10 = 0.03061\n[ 56.9s] wrote /app/solution/v4.parquet\nDONE",
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"command": "cp /app/solution/v4.parquet /app/solution/validation.parquet\n(SLICES=7,14,21,28 EPOCHS=1 NNEG=3000 python run.py test /app/solution/submission_nn.parquet > test.log 2>&1; echo DONE >> test.log) &\nsleep 5; echo launched",
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"file_path": "/app/solution/README.md",
"content": "# Two-tower discovery ranker — \"Made for You\"\n\n## Architecture\n\nA PyTorch two-tower network (`model.py`). The final relevance score is exactly\n`dot(user_vector, item_vector)` with both vectors of dimension 64, so item\nvectors are precomputable offline into a MIPS index and request-time work is a\nsingle user-tower forward pass.\n\n**Shared embedding table** — 80,000 rows: the 30,000 retrieval-catalog tracks\nfollowed by the 50,000 most-played non-catalog tracks (history-only vocabulary),\n`dim = 64`.\n\n**User tower** (`UserTower`) — no user-ID lookup. It reads four weighted bags of\nhistory item ids, pooled with `F.embedding_bag`:\n\n| Channel | Content | Cap | Weighting |\n| --- | --- | --- | --- |\n| 0 | most recent positive listens (`played_ratio_pct >= 50`) | 192 | 21-day recency half-life |\n| 1 | habitual favourites: top items by lifetime play count | 96 | `log1p(count)` |\n| 2 | most recent likes | 96 | uniform |\n| 3 | most recent dislikes | 32 | uniform |\n\nThe four pooled vectors are concatenated (256-d) and passed through\n`Linear(256→256) → GELU → Dropout → Linear(256→256) → GELU → Linear(256→63)`.\nA constant `1.0` is appended as the 64th coordinate.\n\n**Item tower** (`ItemTower`) — input is the item embedding concatenated with six\ncutoff-correct popularity features (log plays in the trailing 7d / 28d /\nall-time window, organic 80%-completion listens and organic likes in 28d, and a\n7d-vs-28d trend ratio), all standardized. Two heads:\n`Linear→GELU→Dropout→Linear` producing 63 dims, plus a small MLP producing the\n64th coordinate, which acts as a learned item bias against the user tower's\npinned `1.0`. The item vector depends only on the item and the serving cutoff,\nnever on the user, so the offline/online split holds.\n\n## Training objective\n\nTraining slices reproduce the evaluation protocol rather than a global\ninteraction matrix — nothing is materialized or factorized over users × items,\nso the method scales to millions of users.\n\nFor each cutoff `T ∈ {C−7d, C−14d, C−21d, C−28d}` (`C` = the stage's cutoff):\n\n* the user tower sees only events strictly before `T`;\n* positives are the user's **new** items (never listened to before `T`) with an\n organic like (weight 2.0) or an organic ≥80%-completion listen (weight 1.0) in\n `(T, T+7d]`, restricted to the retrieval catalog.\n\nThis yields ~198k (history, positive) pairs. The loss is a **sampled softmax**:\nper batch of 1,024 pairs, 3,000 shared negatives are drawn from `popularity^0.75`\nand combined with the in-batch positives; logits carry a `−log q` sampling\ncorrection, duplicates of the true positive are masked out, and the\ncross-entropy is weighted by the grade weight. Batches are drawn within a single\nslice so every candidate shares one cutoff-correct popularity feature vector.\nAdamW, OneCycle LR (max 3e-3), 1 epoch — held-out validation NDCG degrades\nmonotonically past one epoch, so training stops there.\n\nRanking masks each user's ineligible items to `−inf` and emits the top 100.\n\n## Results (public validation window)\n\n| Model | NDCG@10 |\n| --- | --- |\n| Popularity baseline | 0.01071 |\n| **Two-tower (this model)** | **0.03061** |\n\nScored over the 4,263 users with at least one eligible relevant item.\n\n## Commands\n\n```sh\n# validation-stage ranker: history = train_* only, scored against val_*\npython run.py validation solution/validation.parquet\npython /task/evaluate_public.py /app/solution/validation.parquet\n\n# final hidden-test ranker: refit on train_* + val_*, val events are history\npython run.py test /app/solution/submission.parquet\n```\n\n## Files\n\n* `data_utils.py` — parquet/eligibility loading.\n* `features.py` — cutoff-correct user history channels, training targets,\n vocabulary, and `PopStats` item popularity features.\n* `model.py` — `UserTower`, `ItemTower`, `TwoTower`.\n* `run.py` — end-to-end train + rank for either stage.\n* `validation.parquet` — validation-stage ranking (score above).\n* `submission.parquet` — final hidden-test deliverable.\n"
},
"result": {
"timestamp": "2026-08-29T02:55:16.373Z",
"content": "File created successfully at: /app/solution/README.md (file state is current in your context — no need to Read it back)",
"isError": false
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"name": "Bash",
"input": {
"command": "sleep 75; cat /app/solution/test.log | grep -E \"slice|epoch|wrote|DONE|Error|Trace\" | tail",
"description": "Check test refit progress"
},
"result": {
"timestamp": "2026-08-29T02:56:33.863Z",
"content": "[ 17.3s] slice -7d: 48857 pairs\n[ 19.7s] slice -14d: 50814 pairs\n[ 22.1s] slice -21d: 50113 pairs\n[ 24.4s] slice -28d: 49054 pairs\n[ 27.3s] epoch 0 step 0/191 loss 20.5643\n[ 47.5s] epoch 0 done, loss 19.5593\n[ 50.9s] wrote /app/solution/submission_nn.parquet\nDONE",
"isError": false
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{
"id": 38,
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"timestamp": "2026-08-29T02:56:35.697Z",
"blocks": [
{
"kind": "message",
"timestamp": "2026-08-29T02:56:35.697Z",
"text": "Test refit completed. Validating the submission against the test eligibility contract before installing it."
},
{
"kind": "tool",
"timestamp": "2026-08-29T02:56:39.454Z",
"callId": "toolu_01Eo48xELccTcf5AK1vbKa7j",
"name": "Bash",
"input": {
"command": "python -c \"\nimport sys; sys.path.insert(0,'/task')\nfrom pathlib import Path\nimport pandas as pd, numpy as np\nfrom ranking_evaluation import CandidateSet, validate_ranking, read_ranking\ntg = set(pd.read_parquet('/task/data/target_users.parquet').uid.astype(int))\nf = validate_ranking(read_ranking(Path('submission_nn.parquet')), tg)\nel = CandidateSet(Path('/task/data/test_eligible_candidates.npz'))\nbad = sum(1 for u,i in f[['uid','item_id']].itertuples(index=False,name=None) if not el.is_eligible(u,i))\nprint('rows',len(f),'users',f.uid.nunique(),'ineligible',bad)\nassert bad==0\nf.to_parquet('submission.parquet',index=False)\nprint('installed submission.parquet')\n\" && rm -f smoke.parquet v2.parquet v3.parquet validation_pop.parquet v2_ep*.parquet v3_ep*.parquet v4_ep*.parquet validation_ep*.parquet && ls -la",
"description": "Validate and install final submission"
},
"result": {
"timestamp": "2026-08-29T02:56:42.165Z",
"content": "rows 845600 users 8456 ineligible 0\ninstalled submission.parquet\ntotal 4896\ndrwxr-xr-x 1 agent agent 4096 Aug 29 02:56 .\ndrwxr-xr-x 1 agent agent 4096 Aug 29 02:29 ..\n-rw-r--r-- 1 agent agent 4027 Aug 29 02:55 README.md\n-rw-r--r-- 1 agent agent 1930 Aug 29 02:34 data_utils.py\n-rw-r--r-- 1 agent agent 9712 Aug 29 02:42 features.py\n-rw-r--r-- 1 agent agent 3326 Aug 29 02:43 model.py\n-rw-r--r-- 1 agent agent 9468 Aug 29 02:49 run.py\n-rw-r--r-- 1 agent agent 1187069 Aug 29 02:56 submission.parquet\n-rw-r--r-- 1 agent agent 1187069 Aug 29 02:55 submission_nn.parquet\n-rw-r--r-- 1 agent agent 410 Aug 29 02:55 test.log\n-rw-r--r-- 1 agent agent 806 Aug 29 02:48 v2.log\n-rw-r--r-- 1 agent agent 959 Aug 29 02:52 v3.log\n-rw-r--r-- 1 agent agent 440 Aug 29 02:54 v4.log\n-rw-r--r-- 1 agent agent 1283394 Aug 29 02:54 v4.parquet\n-rw-r--r-- 1 agent agent 1283394 Aug 29 02:54 validation.parquet",
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"input": {
"command": "rm -f v4.parquet submission_nn.parquet v2.log v3.log v4.log && python /task/evaluate_public.py /app/solution/validation.parquet",
"description": "Final validation score check"
},
"result": {
"timestamp": "2026-08-29T02:56:48.061Z",
"content": "{\n \"model\": \"/app/solution/validation.parquet\",\n \"scores\": {\n \"quality_ndcg@10\": 0.030608,\n \"quality_users\": 4263\n }\n}",
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"text": "Done. `/app/solution/submission.parquet` is written and validated against the test contract (845,600 rows, 8,456 users, ranks 1–100, zero ineligible items).\n\n**Model** — PyTorch two-tower net, score is exactly `dot(user_vec, item_vec)` at dim 64:\n- **User tower**: no user-ID lookup. Four recency/count-weighted `embedding_bag` pools over history (recent positive listens, habitual top items by play count, likes, dislikes) → concat → 3-layer MLP → 63 dims + a pinned constant `1.0`.\n- **Item tower**: shared embedding + six cutoff-correct popularity features (7d/28d/all-time plays, 28d strong listens, 28d organic likes, 7d-vs-28d trend) → MLP → 63 dims + a learned item-bias coordinate that pairs with the user tower's constant. Item vectors depend only on item + serving cutoff, so they precompute into a MIPS index.\n- **Training**: four 7-day time slices before each stage cutoff. Positives are *new* items (never consumed before the cutoff) with an organic like (weight 2) or organic ≥80% listen (weight 1) — mirroring the graded objective and the eligibility rule, which excludes already-consumed items. Sampled softmax with 3,000 shared `pop^0.75` negatives plus in-batch positives, `−log q` corrected. No global user-item matrix is ever built or factorized.\n\n**Scores**: popularity baseline 0.01071 → two-tower **0.030608** validation NDCG@10 (4,263 scored users). Final model refit on `train_* + val_*` with val events as history.\n\nTwo notes on what I found and acted on:\n- Only ~21% of in-catalog relevant validation items are eligible — eligibility strips already-consumed tracks, so this is genuine discovery and repeat-consumption features are dead weight. Training targets were restricted to new items to match.\n- Validation NDCG degrades monotonically past one epoch across three configurations (including a heavily regularized dim-48 / dropout-0.3 variant), so training stops at one epoch. That was measured, not assumed — the per-epoch scoring hook is in `run.py`. With more time the obvious next lever is enlarging the training signal (extra self-supervised next-item pairs) rather than more epochs on the current 198k pairs."
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}