Claude Code in Complex Refactoring
Event/Interaction #1
Agent (Claude Code, powered by models like Opus 4.5 or Sonnet 4.5) is tasked with implementing a new feature in an existing microservice, with explicit constraints provided (e.g., via context.md reinforcing separation of concerns).
Typically produces architecturally sound code; plans multi-file changes, identifies interdependencies, and maintains long-term maintainability. In tests, it handles large refactors (e.g., across 15-20 files) with minimal regression, often generating a step-by-step plan before execution.
Strong reasoning capabilities from RLHF tuning for deep analysis and tool use; large context window allows full project awareness, reducing "lazy" shortcuts.
Use constraint injection (e.g., context.md with "Hard Constraints") to guide it as a "junior dev"; its agentic mode (planning + autonomous execution) naturally incorporates this, leading to 75% success rate on codebases over 50k LOC.