Building API Gateway Overview Create an API gateway that provides unified entry point routing, load balancing, authentication enforcement, rate limiting, request transformation, and response aggregation across multiple backend microservices. Support path-based and header-based routing, circuit breaker protection for downstream services, and centralized cross-cutting concern management. Prerequisites - Multiple backend API services with known endpoints, health check URLs, and authentication requirements - Gateway framework: Express Gateway, Kong (declarative config), KrakenD, or custom Node.js…