I've had this happen before, but I think there was a disconnect between the recruiter and the hiring manager. Discussion with the recruiter seemed to go very well. Was asked to complete a coding exercise and given the advice to take my time and do it right. After spending roughly 8-10 hours on it, I submitted it via Github and then got a cryptic message back that they were going with other candidates. Because of the "pull request", I could see that they never even looked at my submission and since this is a position they appear to always be hiring for, I assume other aspects of my background ruled me out. It would have been nice to know that before spending my time on the assignment.