About
The Defense-in-Depth skill provides a robust framework for hardening software by moving beyond single-point validation. It guides the implementation of checks at every layer data passes through—including entry points, business logic, environment guards, and debug instrumentation—to make specific classes of bugs structurally impossible to reproduce. This approach is particularly effective for mission-critical systems where refactoring, mocks, or complex code paths might otherwise bypass traditional single-layer security checks.