AI Codebase Deep Modules

Turn “a web of shallow, cross-importing files” into a codebase that is easy for AI (and humans) to navigate, change, and test.

This skill is built around four ideas:

The codebase matters more than the prompt. AI struggles when feedback is slow, structure is unclear, and dependencies are tangled.
Match the filesystem to the mental model. Group code the way you think about it (features/domains/services), not as a grab-bag of utilities.
Prefer deep modules. Lots of implementation behind a small, well-designed public interface.
Treat deep modules as greyboxes. Lock behaviour with tests at the boundary; internal code becomes replaceable.

When to use this skill

Use this skill when the user wants any of the following: