소개
The Defense-in-Depth skill provides a robust framework for preventing bugs caused by invalid data propagation. Instead of relying on a single validation point, this skill guides the implementation of checks across four distinct layers: entry points, business logic, environment guards, and debug instrumentation. This methodology makes bugs structurally impossible to reproduce by ensuring that data is verified at every stage of execution, providing resilience against refactoring errors, bypasses via mocks, and platform-specific edge cases.