pantheon-ai/design-principles

Apply SOLID principles (SRP, OCP, LSP, ISP, DIP) for tactical class design, method extraction, and interface definition. Use when reviewing class design, refactoring code for maintainability, or designing interfaces and abstractions.

Apply Clean Architecture principles to define layer boundaries, identify dependency violations, and structure domain vs infrastructure code. Use when designing service boundaries, separating business logic from infrastructure, evaluating hexagonal/onion/ports-and-adapters architecture, structuring module layout, or resolving dependency inversion and circular dependency issues.

Select and apply structural design patterns (Strategy, Factory, Adapter, Observer, etc.) to reduce complexity in class design. Use when evaluating whether a pattern solves a concrete problem, refactoring conditional logic, dealing with too many if/else statements or code smells, resolving inheritance problems, or deciding how to structure classes.

Design code for testability using boundary isolation, dependency injection, and testable architecture patterns. Use when designing test strategies, writing unit tests, improving test coverage, refactoring untestable or hard-to-test code, working with mocking or test doubles, or applying TDD practices.