We study how coding agents can improve their own decisions—and the strategies they use to improve. Our research focuses on curating high-quality (accurate and concise) trajectories for training coding agents: solving repository-level software engineering tasks with fewer unnecessary actions and better use of computation.
SI2CA explores self-improvement at two levels:
We evaluate these methods on SWE-bench Verified, SWE-bench Pro, and DeepSWE, studying task success, trajectory conciseness, computational cost, and downstream training.
We also validate the effectiveness of our data curation through supervised fine-tuning of a smaller model, Qwen3.5-35B-A3B-Base. Compared with training on standard rollouts, training on Self-Judgement-curated trajectories yields higher task accuracy and fewer average turns on SWE-bench Verified and the Python subset of SWE-bench Pro. These results show that the curated trajectories provide better training data, helping a smaller coding agent solve more tasks with fewer steps.