AWS API Gateway Advanced

AWS API Gateway is a managed service for creating and managing REST, HTTP, and WebSocket APIs. It sits in front of backend services (Lambda, EC2, Fargate, DynamoDB) and handles routing, authentication, rate limiting, caching, request/response transformation, and monitoring. Advanced mastery covers caching strategies (by query param, by user), custom authorizers (JWT validation), request/response mapping (VTL), WAF integration (DDoS protection), and observability (CloudWatch, X-Ray).