Domande di colloquio per Senior Software Engineer - Java Developer presso NavVis

A recruiting web site had sent my CV to them. We had scheduled an interview with their HR, but unfortunately, she did not come without any reasonable excuse. The recruiter asked me to set another interview session with them. Finally, the second interview happened with the HR. The interview was good and she sent me a technical challenge. I did the challenge and sent to them. In my mind the thing that I did was perfect, but after 6 days they sent me a very short response and rejected me without any sensible feedback. In my opinion, their manner was not professional, and I expect at least a useful feedback!!