API Gateway
Central entry point managing API traffic, security, and routing.
Definition
An API gateway serves as a single entry point for API requests, handling cross-cutting concerns like authentication, rate limiting, routing, and monitoring. Rather than clients connecting directly to multiple backend services, they connect to the gateway which routes requests appropriately.
Gateways provide security benefits, operational visibility, and development efficiency by centralizing concerns that would otherwise be duplicated across services.
Why It Matters
API gateways simplify client development, improve security posture, and provide essential operational visibility. As applications grow more distributed, gateways become essential infrastructure.
For API-driven businesses, gateways enable monetization, access control, and usage analytics that support commercial API offerings.
Examples in Practice
Implementing an API gateway allowed the team to add authentication and rate limiting to 20 microservices without modifying each service individually.
The gateway's request logging revealed that 30% of API traffic came from deprecated endpoints, guiding sunset planning and client migration prioritization.
A graduated rate limiting policy implemented at the gateway protected backend services from aggressive client behavior that had previously caused outages.