Is an API gateway a single point of failure?

It can be if not designed for high availability. Production gateways run multiple instances behind a load balancer with health checks and auto-scaling. Managed services (AWS API Gateway) handle this automatically.

What is the Backend for Frontend pattern?

BFF creates a separate API gateway for each client type (web, mobile, third-party). Each gateway aggregates and transforms data specifically for that client, avoiding the "one size fits all" problem of a single gateway.

Should the API gateway contain business logic?

No. The gateway should handle cross-cutting concerns (auth, rate limiting, routing) only. Business logic belongs in the microservices. Putting logic in the gateway creates a "smart pipe" anti-pattern that is hard to test and maintain.

API Gateway Pattern Explained

The single entry point that shields clients from microservices complexity while handling authentication, routing, and rate limiting.

API Gateway Pattern

An API gateway is a server that acts as the single entry point for all client requests to a microservices backend, handling cross-cutting concerns like authentication, rate limiting, routing, and response aggregation.

Explanation

Without an API gateway, clients must know the address of every microservice, handle authentication with each one separately, and make multiple calls to compose a single view. An API gateway sits between clients and services, providing a unified interface that hides the complexity of the backend architecture. The gateway handles cross-cutting concerns that would otherwise be duplicated across every service: authentication and authorization (verify tokens once at the gateway), rate limiting (throttle abusive clients before they reach services), request routing (map public URLs to internal services), protocol translation (expose REST to clients while services use gRPC internally), response aggregation (combine data from multiple services into a single response), and SSL termination. Popular API gateway implementations include Kong (open source, Lua/Nginx-based), AWS API Gateway (fully managed), Envoy (high-performance proxy, often used with service meshes), and Traefik (container-native, auto-discovery). The Backend for Frontend (BFF) pattern uses multiple gateways — one per client type (web, mobile, third-party) — each tailored to that client's needs.

Bookuvai Implementation

Bookuvai deploys API gateways for all microservices projects, handling authentication, rate limiting, and request routing at the edge. Our standard gateway configuration includes JWT validation, per-client rate limits, request/response logging, and circuit breaking for downstream services. For multi-platform projects, we use the BFF pattern with separate gateways for web and mobile clients.

Key Facts

Single entry point for all client requests to microservices
Handles authentication, rate limiting, routing, and SSL termination
Backend for Frontend (BFF) uses separate gateways per client type
Kong, AWS API Gateway, and Envoy are popular implementations
Eliminates cross-cutting concern duplication across services

Related Terms

Frequently Asked Questions

Is an API gateway a single point of failure?: It can be if not designed for high availability. Production gateways run multiple instances behind a load balancer with health checks and auto-scaling. Managed services (AWS API Gateway) handle this automatically.
What is the Backend for Frontend pattern?: BFF creates a separate API gateway for each client type (web, mobile, third-party). Each gateway aggregates and transforms data specifically for that client, avoiding the "one size fits all" problem of a single gateway.
Should the API gateway contain business logic?: No. The gateway should handle cross-cutting concerns (auth, rate limiting, routing) only. Business logic belongs in the microservices. Putting logic in the gateway creates a "smart pipe" anti-pattern that is hard to test and maintain.