Having 5 years professional experience with Clojure, I applied a few months ago to a remote Clojure job, and the coding test was none other than recursion via zippers, literally my weakest point. I could have done the job just fine since they said they didn’t use zippers on the job, but failed the test and they passed on me. Coding tests are the real problem. I’ve had some great ones where you can tell someone put effort into it and will review it fairly, and I’ve had some that were hacked together like this one where it’s clear they weren’t given enough time to put it together by their superiors.