AI-specific design patterns and system tactics — Feature Store, Champion-Challenger, Shadow Deployment, Drift Detection, Explainability Wrapper, Canary Deployment, Bulkhead, and traditional patterns adapted for AI. This skill should be used when the user asks to "select AI design patterns", "apply ML patterns", "design drift detection", "implement feature store", "plan shadow deployment", "design champion-challenger", "select availability tactics for AI", or mentions AI anti-patterns, maintainability tactics, fault recovery for models, or pattern selection for ML systems.