I do this as well. This helps get the API right very easy on. When building services for my work, we've paired this with Swagger (using Compojure-API in Clojure

I do this as well. This helps get the API right very easy on. When building services for my work, we've paired this with Swagger (using Compojure-API in Clojure) to get clickable API consoles. The end result is fast iteration on an api contract (between us and our consumers) and once we have bound that api contract, we can focus on rewriting the data persistence namespace however is best suited. Often this involves nothing more than adding a line to our DI system to get a database handle in our http request and then for any background worker threads (plus the obvious writing of db-specific routines).