Skywork-SWE: Unveiling Data Scaling Laws for Software Engineering in LLMs
Paper · 2025 · Liang Zeng, Yongcong Li, Yuzhen Xiao et al.
Summary
Training LLM agents to fix real GitHub issues is held back by scarce data. Every task needs an executable environment and validated unit tests, and building these by hand is slow, so most public SWE datasets have only a few thousand instances. The authors created an automated, incremental pipeline with three stages: collecting and pre-filtering candidate pull requests, validating them by execution in Docker runtime images, and generating agent trajectories. The result is the Skywork-SWE dataset of 10,169 Python tasks from 2,531 repositories. Each task has a natural-language description and its own environment image for automatic test checking. They fine-tuned Qwen2.5-Coder-32B inside the OpenHands framework on more than 8,000 successful trajectories. Performance on SWE-bench Verified rose steadily, roughly log-linearly, as training data grew, with no plateau in sight. This is evidence that data scaling laws apply to software engineering agents and that execution-grounded data is the main bottleneck. The released Skywork-SWE-32B model narrows the gap between open and proprietary systems.
Key points
- Dataset scale: Skywork-SWE contains 10,169 runtime-validated Python instances from 2,531 repositories. Repositories that appear in SWE-bench Verified were excluded to avoid leakage.
- Single-attempt result: After fine-tuning on 8,209 trajectories, Skywork-SWE-32B reaches 38.0% pass@1 on SWE-bench Verified with a single attempt, no verifier and OpenHands v0.32.0. This is a new best among Qwen2.5-Coder-32B-based OpenHands agents.
- Test-time scaling: With test-time scaling the score rises to 47.0%. This beats earlier sub-32B results, such as Devstral-Small-2505 at 46.8%.
- Practical lessons:
- Environment images for the 500 Verified tasks need about 1,000 GB of disk.
- Running rollout and validation in mini-batches lets the same images be reused for both steps.
- Results vary noticeably between OpenHands versions.
- Trajectories with more than 50 interaction rounds can exceed the model's 32K-token context.
- Release and future work: The model weights are published on Hugging Face (Skywork/Skywork-SWE-32B). Proposed next steps are multilingual benchmarks such as Multi-SWE-Bench and online RL that uses test-verified rewards.
Fields, topics and concepts
📚 Shelves 5The field of science this work belongs to (OpenAlex fields).Computer Science · 16,667 worksArtificial Intelligence · 16,194 worksArts and Humanities · 16,039 worksLanguage and Linguistics · 15,891 worksInformation Systems · 1,437 works
🧭 Topics 2Research subjects and languages the work is about.Language models & pretraining · 3,320 worksCode & programming languages · 129 works
Cite
Cite as Liang Zeng, Yongcong Li, Yuzhen Xiao, Changshi Li, Chris Yuhao Liu, Rui Yan, Tianwen Wei, Jujie He, Xuchen Song, Yang Liu and Yahui Zhou. 2025. Skywork-SWE: Unveiling Data Scaling Laws for Software Engineering in LLMs. arXiv:2506.19290.
@misc{zeng2025skywork,
title = {{Skywork-SWE: Unveiling Data Scaling Laws for Software Engineering in LLMs}},
author = {Liang Zeng, Yongcong Li, Yuzhen Xiao, Changshi Li, Chris Yuhao Liu, Rui Yan, Tianwen Wei, Jujie He, Xuchen Song, Yang Liu and Yahui Zhou},
year = {2025},
doi = {10.48550/arxiv.2506.19290},
eprint = {2506.19290},
archivePrefix = {arXiv},
url = {https://doi.org/10.48550/arxiv.2506.19290}
}References
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