Refactoring Codex CLI Code for Production

Codex generates functional but poorly structured code — long functions that do multiple things, global state, and no separation between I/O and logic. Variable names are sometimes single-letter or overly abbreviated. There's typically no module structure — everything ends up in one or two files

Separate I/O from business logic so the core functions are pure and testable. Break long functions at natural boundaries — aim for functions under 30 lines. Create a module structure that groups related functions. Replace single-letter variables with descriptive names. Add type annotations if the generated code lacks them

Not all Codex CLI code needs refactoring. If it works, is secure, and you don't need to modify it, leave it alone. Refactor when: you need to add features and the current structure makes it difficult, bugs keep appearing in the same area of code, or onboarding new developers takes too long because the code is hard to understand.

The golden rule of refactoring: behavior stays the same, structure changes. Before refactoring any code, make sure you have tests covering the current behavior (or add them first). Refactor in small steps — change one thing at a time and verify the app still works. Use version control (git) to commit after each successful change so you can revert if something breaks.

A well-organized project has a predictable structure where anyone can find what they're looking for. Group files by feature (not by type), keep related code together, and use clear naming. Every file should have a single clear purpose. If you can't describe what a file does in one sentence, it's probably doing too much and should be split.