The interview process was uneven. A phone screen by the recruiter followed by an hour-long interview by the hiring manager went well. Feedback came as and when promised.
The onsite interview went on for a few hours and I thought that it was well-organized and logical. I met with the appropriate people and the questions were all reasonable. I answered some well and others could have been better.
After the interview, the hiring manager and the recruiter both promised feedback and a decision within a week. 3 weeks passed without my hearing anything. I sent email to each of them. Still nothing. Finally, I contacted the person at the company who scheduled the interview. She "apologized on behalf of the recruiter", saying that he should have been in contact with me all through the process. Up until the interview, I thought that the process went well but it's unprofessional to give an explicit expectation and not meet it.
I understand if they don't believe me to be the best fit. I don't understand their failure to get back to me or reply to me email.