improve-codebase-architecture

To improve codebase testability, you refactor shallow modules by identifying tightly-coupled code and consolidating it into deep, high-leverage architectural components with clearer domain boundaries and better locality of change.

A shallow module in software architecture is a component with a small interface but complex, tightly-coupled internal implementation that lacks locality, making it difficult to test and navigate across multiple files for a single process.

You consolidate scattered business logic by identifying the architectural seam where the code intersects, then refactoring those shallow, tightly-coupled modules into a single deep module with high leverage.

Yes, architecture refactoring requires adherence to the project's domain language and existing architectural decision records to ensure consistent refactoring outcomes and preserve established domain boundaries.

The best way to compare interface designs is by using parallel sub-agent patterns to explore and evaluate multiple interface options for a single module, ensuring the final refactored component provides optimal architectural leverage.