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API Gateway Pattern

Single entry point for routing, aggregation, and cross-cutting concerns

What is API Gateway Pattern?

An API Gateway is a single entry point for client requests. It routes requests to appropriate backend services, aggregates responses, and handles cross-cutting concerns like authentication, rate limiting, logging, and request transformation. It simplifies client code and centralizes common logic.

Related patterns: Microservices Architecture, Event Driven Architecture, CQRS Pattern, Domain Driven Design

Key Components of API Gateway Pattern Architecture

ComponentDescription
RouterRoutes requests to appropriate backend services
AuthenticationCentralized auth and authorization
Rate LimiterThrottling and rate limiting
Request AggregatorCombines responses from multiple services
Protocol TranslatorTranslates between REST, gRPC, GraphQL
ObservabilityLogging, monitoring, tracing

When to Use It

  • Multiple backend services exposed to clients
  • Need for centralized authentication/authorization
  • Rate limiting and throttling requirements
  • Request/response transformation
  • API versioning and backward compatibility

API Gateway Architecture in Practice

Technology Stack

Gateway Platforms

KongAzure API ManagementAWS API Gateway

Runtime / Proxy

OcelotEnvoyNGINX

Backend Services

.NETNode.jsSpring Boot

Observability

PrometheusGrafanaOpenTelemetry

Benefits

  • Single entry point simplifies client integration
  • Centralized auth, logging, and monitoring
  • Request routing and load balancing
  • Protocol translation (e.g., REST to gRPC)
  • Reduced round trips via response aggregation
  • API versioning and backward compatibility
  • Simplified client—no direct service discovery

Challenges

  • Single point of failure if not designed for HA
  • Potential bottleneck—must scale horizontally
  • Additional latency for routing/transformation
  • Gateway logic can become complex
  • Team ownership and deployment coordination
  • Gateway can become a monolith if overused

Real World Example

Mobile App Backend

A mobile app calls one API gateway. The gateway authenticates the user, routes to User, Product, and Order services, aggregates responses where needed, and applies rate limits. The app never talks to individual services directly. High traffic handled with gateway scaling and backend isolation.

Services

  • User Service
  • Product Service
  • Order Service

Communication

  • Single API endpoint for all client requests
  • Gateway routes by path and method
  • Response aggregation for composite views

API Gateway Pattern Consulting Services

We help organizations design and implement API gateways for unified, secure, and scalable API exposure.

  • API Gateway architecture design
  • Kong, Azure API Management, or AWS API Gateway implementation
  • Authentication and rate limiting strategies
  • Request aggregation and BFF patterns
  • API versioning and migration

Frequently Asked Questions

Need Help Designing an API Gateway Architecture?

Our architects can help you design unified API exposure, authentication, rate limiting, and scalable gateway patterns.