Casumo Full-Stack Developer interview questions

I did first 'interview' of around 20 minutes with company recruiter. Got selected to do a test in which they asked me to implement a Java application (REST service). I implemented the application in the correct manner and they decided not to move with my application only citing a one liner saying that the application logic was contained in only one class, when this was not the case. Clearly, it shows that they don't bother getting to know the person, what projects he or she worked on and his personality.