defense-in-depth

Multi-layer validation catches bugs across four sequential stages: type checking and linting, unit tests, integration tests, and end-to-end checks. Run each layer before deployment to enforce code quality across static analysis, unit coverage, integration workflows, and full system verification.

Unit tests validate individual components in isolation. Integration tests verify interactions between modules. End-to-end tests confirm the entire workflow functions correctly. A four-layer pipeline applies all three sequentially to catch bugs at different abstraction levels.

Yes. A multi-layer validation pipeline automates type checking, linting, unit tests, integration tests, and end-to-end checks as a single workflow. Each layer runs in sequence with recovery procedures, preventing code changes and bug fixes from reaching production without passing all checks.

End-to-end testing validates complete user workflows and system behavior under real conditions. Use it after unit and integration tests pass to confirm the entire application functions as intended before production deployment.

Each layer in the pipeline includes recovery procedures to handle failures. When code fails validation—whether in type checking, unit tests, integration tests, or end-to-end checks—recovery steps guide remediation before the next deployment attempt.

Run the four-layer validation pipeline before marking work complete. Apply it consistently across code changes, bug fixes, and feature work to ensure every modification passes linting, type checking, unit tests, integration tests, and end-to-end verification.