improve-codebase-architecture

Shallow modules are located by applying the deletion test to find interfaces failing to capture behavior for tests and callers. The skill analyzes your codebase to find these deepening opportunities where complexity concentrates across tightly coupled module seams.

Improve testability by classifying dependencies and choosing seam placement using ports and adapters, including mockable and in-memory test seams. This ensures testing matches the interface and moves behavior behind a smaller, deeper module boundary.

Make a codebase AI-navigable by deepening shallow modules so their interfaces capture behavior for tests and callers. Consolidating tightly coupled modules increases depth and locality, allowing AI to explore system behavior more effectively behind clear boundaries.

The deletion test works by locating shallow modules whose interfaces fail to capture behavior for testing and callers. It indicates where complexity would concentrate if the module were removed, producing candidates for deepening and alternative interface design.

Yes, alternative interface designs can be generated by requesting the optional design it twice pattern during the interactive grilling loop. The skill proposes deepened module shapes and alternative interface options after exploring codebase candidates through the deletion test.

Module deepening is not suitable when shallow interfaces already capture sufficient behavior for tests and callers without friction. If dependencies cannot be cleanly categorized into ports and adapters, deepening may spread complexity rather than consolidating tightly coupled modules.