The first assignment was writing an algorithm for managing a job queue according to some precedence rules involving job and worker properties. Input and output were JSON formatted data over stdin/stdout and my solution used native collections and car/cdr style recursion.

They said it was OK and asked me to turn it into a REST web service as the second part of the assignment. Now I had to keep score between calls but sharing data using a global structure goes against every fiber of my developer muscles so I picked a database. I'm no clojure expert but I guess in the real world most REST APIs are using databases under the hood instead of atoms.