Opower Senior Software Engineer interview questions

I applied online and was contacted by one of their recruiter. After spending some time going over the ususal discussion of my past experience and responsibilities I was told that the next stage of the interview process is a coding exercise. The assignment itself is not too difficult and require knowledge of some design patterns and callback structures with proper threading,but the instructions say that the solution should look like a 'production level' solution. So after spennding 5 days including a weekend to make sure that I am using property files to pick up attributes, using log4j for proper logging and making sure sifficient application progress is logged at proper log level, using sufficient jUnit and Mocito to add unit tests with runtime mocking of my service layer, adding a design document with proper UML class diagram and more, I submit the assignment. After submitting I received the instruction from the recruiter that I would hear back in 72 hours. After nine(9) days when I still haven't heard anything back, I email the recruiter again to see if I am still being considered for further interviews I get a response saying that it was decided that my background might not be best fit for the position and I am not being considered anymore. I would have preferred to get atleast some feedback for the 5 day long task I was given and some response as to what exactly was lacking or missing from my solution and if it wasn't my code that made them decide that I wasn't fit then perhaps a few more behavioral interviews before the coding exercise would seem more appropriate.