API Gateway vs Direct Service Exposure

A shopping app is built from twelve microservices. When a user opens the home screen, the app needs data from five of them: the user profile, recommendations, the cart, recent orders, and notifications.

The app can call those five services directly. Or it can make one call to a single entry point, which calls the five services for it.

This is the choice between direct service exposure and an API gateway. Both approaches still need the same shared work, like checking login tokens and limiting traffic