In this first example, we'll go through the steps to set up a simple integration with an existing API. What is neat about API Gateway is that it's possible to go a very long way on the path to replacing current application code without writing any code ourselves.
Note
In these examples, we'll use a publicly available fake API called JsonPlaceholder, pretending for our purposes that it's a legacy API that we'd like to replace: https://jsonplaceholder.typicode.com.
Of course, this type of replacement warrants plenty of thought and careful planning. Authentication, rate limiting, DNS entries, and the like are all factors that much be thought through carefully before embarking on such a project. Still, with all of the issues that one should consider, there are many tools and options to make this pattern a real possibility for many applications.