api-gateway-patterns

API gateway routing directs incoming requests to appropriate microservices based on path, header, or host criteria. Configure routing rules to map `/users` requests to your user service and `/orders` to your order service, centralizing traffic management and eliminating client-side service discovery complexity.

Centralize authentication at the gateway by validating JWT tokens, OAuth 2.0 credentials, or API keys before requests reach microservices. This enforces consistent security policies, reduces duplicate authentication logic across services, and simplifies credential management and token refresh workflows.

Rate limiting, circuit breakers, and retry logic are implemented at the gateway layer to protect backend services from overload and cascading failures. These policies enforce traffic quotas per client, gracefully degrade during service outages, and automatically retry failed requests based on configurable thresholds.

Yes. An API gateway enables BFF patterns by aggregating data from multiple microservices and applying mobile-specific transformations, authentication, and response formatting in a single layer. This reduces client complexity and network round trips while centralizing cross-cutting concerns like logging and CORS.

API gateways transform requests and responses to adapt data formats, add headers, aggregate service responses, or apply protocol conversions. Transformation at the gateway ensures consistent API contracts for clients while allowing internal microservices to evolve independently.

Use an API gateway when you need centralized routing, authentication, rate limiting, and policy enforcement across multiple services. Direct communication suits point-to-point scenarios, but gateways reduce complexity, improve security, and provide operational visibility in microservices architectures.