AI Regression Testing provides specialized testing strategies and patterns designed for AI-assisted development where the same model writes and reviews code, creating systematic blind spots. It details sandbox-mode API testing without database dependencies, test helpers for Next.js app routes, and automated bug-check workflows to catch sandbox and production path inconsistencies. Use this skill when adding regression coverage to AI-assisted code, or when the same model both wrote and reviewed a change and you need to prevent re-introduction of bugs.