Hiring process was not coordinated properly. Process for Phone and Skype interview took 3 months and no updates were provided by the recruiter. Recruiter could have been bit responsible in updating me with the status of the interview. Interview with the hiring manager was never on time. Had to reschedule a couple of times.

Multiple rounds of interviews - starting with the actual people you will be working with (good questions). Last round will be with Sr. management, where the worst questions come from - they do not even know the answers themselves!