Loading...
Quick Definition
An API gateway is a managed entry point that sits in front of backend services, handling routing, authentication, rate limiting, and monitoring for API requests. In the cloud it simplifies microservices communication but is usage-priced, making request volume a meaningful cost driver.
An API gateway sits between the outside world and your backend services. Every request passes through it, and it handles the repetitive work: routing each call to the right service, checking identity, limiting abusive traffic, and recording what happened.
In a microservices setup, a gateway saves every service from re-implementing the same security and routing logic. The trade-off is cost: gateways are usually priced per request, so a chatty application that makes millions of small calls can turn the gateway itself into a meaningful line on the bill.
Example. A mobile app polls an API every five seconds per user. With 100,000 active users, that is over 1.7 billion requests a month through the gateway. Switching to push notifications cuts request volume, and the gateway bill, by more than 90 percent.
Watch gateway request volume the way you watch compute. Opslyft Cost Visibility breaks usage-priced services like this out of the noise so you can see what drives them.
If you run several services or expose APIs publicly, almost always. A single internal service may not need one.
Cut unnecessary calls, batch small requests, cache responses, and review whether every workload truly needs the gateway in its path.
Request count is the main driver, with data transfer and extra features such as caching adding on top.