system-design

A deep module in software architecture features a simple interface that hides complex implementation details. This design reduces cognitive load and enforces clean boundaries by minimizing the surface area exposed to users.

Design APIs by enforcing a small surface area, keeping implementation details private, and encapsulating knowledge to prevent information leakage. Compare multiple design alternatives before coding to ensure clear separation of concerns.

Yes, these system design principles apply to CLI tools, commands, and plugins. Applying deep module boundaries and information hiding to CLIs ensures robust interfaces, composability, and long-term maintainability across projects.

Red flags of shallow interfaces include exposed internal implementation details, repeated patterns, and a large surface area. These issues increase coupling and cognitive load, making the system harder to maintain over time.

The best way to start building maintainable coding systems is to design twice by comparing multiple alternatives before implementation. Focus on a small surface area, keep implementation private, and establish deep module boundaries.