What problem does it solve?
This skill addresses the common issue of shallow, tightly coupled codebases that are difficult to test, maintain, and navigate. It provides a shared architectural vocabulary to help developers build deep modules that offer high leverage for callers and clear locality for maintainers.
Core Features & Use Cases
- Deep Module Design: Principles for hiding complex implementation behind simple, stable interfaces.
- Seam Identification: Guidance on where to place boundaries to ensure code is testable and swappable.
- Design It Twice: A structured process for exploring multiple interface alternatives before committing to an architecture.
- Use Case: When refactoring a legacy service, use this skill to identify where to place a seam, define a port, and implement an in-memory adapter to make the logic testable without external dependencies.
Quick Start
Use the codebase-design skill to analyze the current module structure and propose a deeper interface for the authentication service.