Amazon API Gateway
- What it is
- Fully managed front door for APIs: create, publish, secure, monitor, and version REST, HTTP, and WebSocket APIs.
- Handles authorization, throttling, request/response transformation, caching, and API keys.
- Common pattern
- API Gateway → AWS Lambda → Amazon DynamoDB is the canonical serverless application stack.
- API types
- HTTP API — cheaper, faster, fewer features. The default for straightforward Lambda proxying.
- REST API — full feature set: request validation, caching, usage plans, API keys, WAF integration.
- WebSocket API — bidirectional, persistent connections for chat and real-time apps.
- Not to be confused with
- AWS AppSync — managed GraphQL, with a single flexible query endpoint and real-time subscriptions.
- load balancers — distribute traffic to compute; API Gateway also manages the API contract, auth, and quotas.