Scaling Coding Agents via Atomic Skills

Atomic skill decomposition: Instead of treating software engineering as monolithic composite tasks, the framework formalizes five fundamental operations that compose into higher-level capabilities. Think of it as teaching an agent the alphabet of coding rather than memorizing specific sentences, enabling flexible recombination across novel task types.

Joint RL across skills: The agents are trained through joint reinforcement learning that optimizes performance across all five atomic skills simultaneously. This joint training produces representations that capture the underlying structure shared across coding operations rather than surface-level patterns tied to specific benchmarks.

Strong generalization to unseen tasks: Joint RL improves average performance by 18.7% across both the five atomic skills and five composite tasks. The improvements transfer to unseen composite tasks including bug-fixing, code refactoring, ML engineering, and code security, none of which were directly optimized during training.

A new scaling paradigm: The work establishes that scaling coding agents through foundational skill mastery is more sample-efficient and transferable than task-level optimization. As the number and complexity of software engineering tasks grow, this compositional approach offers a more sustainable path than continuously expanding task-specific training sets.