This is not new: the API gateway has been used for a long time. A proxy server is one of the most important components of internet applications, routing different requests based on the URI or header information. An example is the Oracle proxy server.

Microservices expose endpoints to communicate and serve requests. Imagine that you have multiple microservies, perhaps 10/100 or more. It would be a clutter of requests across microservices and clients (web, desktop or mobile app and so on). It would be a nightmare to manage with complex and fragile requests (see the following figure for only three clients and three services):