Chapter 8. External API patterns
This chapter covers
- The challenge of designing APIs that support a diverse set of clients
- Applying API gateway and Backends for frontends patterns
- Designing and implementing an API gateway
- Using reactive programming to simplify API composition
- Implementing an API gateway using GraphQL
The FTGO application, like many other applications, has a REST API. Its clients include the FTGO mobile applications, JavaScript running in the browser, and applications developed by partners. In such a monolithic architecture, the API that’s exposed to clients is the monolith’s API. But when once the FTGO team starts deploying microservices, there’s no longer one API, because each service has its own API. Mary and her team must decide what kind of API the FTGO application should now expose to its clients. For example, should clients be aware of the existence of services and make requests to them directly?