I found this opportunity though a recruiter so there was the usual phone chat then coffee catch up. After which the recruiter sent my resume to the client. I was then asked to perform a tech test. I spent about 6 hours completing the test and tweaking my code. I submitted a working solution backed by a suite of relevant unit tests and focussed on not over engineering the solution. Unfortunately the feedback from my test was that they liked my tests and generally my code but they the the thought my implementation was too simple! Simplicity was exactly what I was after! I understood what they wanted me to do and afterwards spent 30 mins tweaking my code to achieve it. Unfortunately they weren't interested in discussing further.