The day after the HR sent me an coding test that involved creating a simple memory game in JS with a tiny back end to store high scores. So I banged out this code as fast as possible, while trying to emphasis on maintainability and testability. I sent back the result as github repo:

https://github.com/m4nuC/memGame

Didn't hear back for a few days but eventually arrived a mail stating that "this code felt far short from a senior developer standards" and obviously didn't get the job. I know I cut a few corners, no unit testing, a couple of minor bug and obviously not a production ready app but I thought that would be enough to show that I knew how to build a web app without spending 2 days on it.

I couldn't manage to get any more info from them on what they meant by "falling far short of senior developer standards" So what in your opinion went so wrong about the code?