Zendesk Software Developer interview questions

Most unprofessional HR I've encountered in my career. She never called since she was stuck on some train. Then asks me for a new time. I send her new time. She never responds back. Next day I check jobvite, says 'Not Selected'. Like wtf? I want to seriously report her incompetence.

The typical format: 1) Recruiter screening 2) Technical screening 3) Onsite The onsite itself was for about a half day, with 4-5 rounds and lunch with the potential boss. In one round, the interviewer literally made up the question on the spot. I had to help him compose the question. In two other rounds, the questions were almost exactly identical. I could tell that they did not coordinate with each other at all before asking me these questions. The last round was a system design question and the interviewer there was nice and polite. I just had a up and down experience with this process. None of the questions were difficult, but none of the questions seem to be prepared either. It was almost too easy and open ended that I'm still trying to figure out what I did wrong. I had extra time to spare in each round, but there wasn't much substance in each question to adequately test my knowledge of the subject matter. No call to explain what happened, just the standard rejection email. Kind of a bummer, and a waste of my time.