Next, we'll walk through a scenario where we have an existing API interface that we need to support, but would like to change the backend implementation entirely. This scenario is common and one I've dealt with personally. Existing clients point to a particular set of API endpoints. Breaking a public API that many developers depend on isn't something anyone wants to do. But, when that API is built on top of hard-to-maintain or poorly performing code, how does one iterate without requiring hundreds or thousands of developers to update their mobile, web, or GUI applications?
In this example, I will walk through the steps necessary to take a pretend legacy API and reimplement it using our modern API. JSONPlaceholder will play the part of our new, modern, scalable, and performant RESTful API. The single URL we will reimplement...