API Gateway
API Gateway
Our application is now made up of many services. One API handles login. Another processes payments. Another manages products. Another retrieves customer profiles. If every service exposes its own API directly to the internet, clients must know dozens of different endpoints. Security becomes difficult. Monitoring becomes difficult. Managing versions becomes difficult. The engineering problem became obvious. How do we provide one secure and intelligent entry point for every API? The engineering concept that solved this problem is the API Gateway. Instead of exposing every service directly, all requests first arrive at the API Gateway. It authenticates users. Validates requests. Limits excessive traffic. Routes each request to the correct backend service. It becomes the single front door for the entire application. Amazon Web Services provides this through Amazon API Gateway. Microsoft Azure provides Azure API Management. Google Cloud provides API Gateway and Apigee for enterprise API management. Different names. One engineering concept. Applications became easier to secure, monitor and manage because every request entered through a single controlled gateway. But another challenge soon appeared. Modern applications weren't just responding to user requests anymore. They were coordinating long-running business processes involving many services. How do multiple services work together to complete one business workflow?