API Gateway
Master the traffic management system that sits between the outside world and your services. One door into your system — handling routing, auth, rate limiting, and observability so your services don't have to.
Core Responsibilities
Routing, load balancing, SSL termination, protocol translation, and request/response transformation.
Authentication & Authorization
API keys, JWT validation, OAuth 2.0, mTLS — the most critical security function of a gateway.
Rate Limiting & Throttling
Token bucket, sliding window, distributed limiting with Redis, and circuit breakers.
Request Lifecycle & Observability
Inbound pipeline, upstream communication, outbound pipeline, logging, metrics, and tracing.
Caching & Service Discovery
Gateway caching strategies, cache invalidation, Consul, Kubernetes discovery, and upstream management.
Security & WebSocket Support
DDoS mitigation, CORS, bot detection, WebSocket proxying, SSE, gRPC, and GraphQL.
Versioning & Traffic Management
API versioning, canary deployments, blue-green, traffic splitting, and deprecation.
Gateway Patterns & Multi-Tenancy
BFF, API composition, sidecar vs centralized, developer portals, and plans.
Implementations & Operations
Kong, AWS API Gateway, Envoy, NGINX, Traefik — comparison, deployment, and production ops.
Why API Gateway?
Without a gateway, every service reimplements authentication, rate limiting, logging, and SSL termination. Clients must know your internal service topology. There's no single place to enforce policies. The gateway solves all of this — one entry point, one place for cross-cutting concerns.
- ✓Single entry point — clients talk to one endpoint, gateway routes to the right service.
- ✓Cross-cutting concerns centralized — auth, rate limiting, logging, CORS handled once.
- ✓Protocol translation — expose REST to clients while backends use gRPC, WebSocket, or queues.
- ✓Traffic management — canary deployments, blue-green, A/B testing without service changes.
- ✓Observability at the boundary — every request logged, metered, and traced from one place.