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SWE-Prime filters noisy trajectories to improve code-solving models

SWE-Prime addresses a fundamental problem in LLM training for code: successful trajectories aren't always good teachers. The method filters training data at two levels, removing inefficient or risky steps that models might otherwise learn to replicate. This matters because software engineering benchmarks like SWE-bench have driven a race to scale trajectory datasets, but raw scale masks quality issues. By pruning noisy supervision before fine-tuning, SWE-Prime suggests that trajectory-based agent training may benefit more from curation than volume, potentially reshaping how teams approach code-solving model development.

Modelwire context

Analyst take

SWE-Prime's contribution isn't that filtering helps (that's obvious), but that the field has been optimizing the wrong variable. Teams racing to scale trajectory datasets may have been paying a hidden cost in noisy supervision that outweighs the benefit of volume.

This connects directly to WikiSkill (released same day), which also targets sample efficiency in agent learning by retaining knowledge across iterations rather than discarding it. Both papers reject the assumption that agent training requires either larger models or more raw data. Where WikiSkill focuses on persistence and reuse, SWE-Prime focuses on filtering what gets learned in the first place. Together they suggest a broader reorientation: the bottleneck in code-solving agents is no longer compute or dataset size, but the quality of the learning signal itself.

If teams adopting SWE-Prime's filtering approach report faster convergence on SWE-bench with smaller trajectory datasets (under 50k examples) than unfiltered baselines within the next six months, that confirms the hypothesis. If performance gains disappear when tested on out-of-distribution code tasks (e.g., real GitHub issues vs. benchmark curated examples), the method is overfitting to the benchmark rather than teaching robust reasoning.

This analysis is generated by Modelwire’s editorial layer from our archive and the summary above. It is not a substitute for the original reporting. How we write it.

MentionsSWE-Prime · SWE-bench

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This synthesis and analysis was prepared by the Modelwire editorial team. We use advanced language models to read, ground, and connect the day’s most significant AI developments, providing original strategic context that helps practitioners and leaders stay ahead of the frontier.

Modelwire summarizes, we don’t republish. arXiv cs.CL originally reported this story as SWE-Prime: Fewer Trajectories, Better Performance”. The full content lives on arxiv.org. If you’re a publisher and want a different summarization policy for your work, see our takedown page.

SWE-Prime filters noisy trajectories to improve code-solving models · Modelwire