api-gateway-patternslisted

# API Gateway Patterns Expert guidance for implementing API gateways with routing, authentication, traffic management, and service composition patterns for microservices architectures at scale. ## When to Use This Skill - Implementing API gateway infrastructure for microservices - Designing Backend for Frontend (BFF) layers - Adding authentication and authorization at the gateway level - Implementing rate limiting, circuit breakers, and retry logic - Setting up service discovery and dynamic routing - Building API composition and aggregation layers - Managing cross-cutting concerns (logging, monitoring, CORS) - Evaluating gateway solutions (Kong, Nginx, Envoy, AWS API Gateway) ## Core Concepts ### Gateway Responsibilities **Routing**: Direct requests to appropriate backend services based on path, headers, or host **Security**: Centralized authentication, authorization, and API key validation **Traffic Management**: Rate limiting, circuit breakers, retry logic **Composition**: Aggregate multiple service calls into unified responses **Transformation**: Modify requests/responses for client optimization or legacy adaptation ### Architecture Patterns **Single Gateway**: One gateway for all clients (simple, potential bottleneck) **BFF Pattern**: Separate gateway per client type (mobile, web, admin) - optimized for each **GraphQL Gateway**: Schema stitching across services, client-driven data fetching **Service Mesh**: Distributed gateway pattern with sidecar proxies (Istio, Li