Codebase Design

Design deep modules: a lot of behaviour behind a small interface, placed at a clean seam, testable through that interface. Use this language wherever code is being designed or restructured. The aim is leverage for callers, locality for maintainers, and testability for everyone.

This is the design language. tech-debt inventories; structural-review judges a diff; this skill names the shape. It also runs the survey modes: a read-only senior-advisor pass over a whole codebase that hands back plans for other agents, a written analysis, or ranked deepening candidates. Vocabulary needs no mode; surveys run only when asked.

Modes