I arrive 10 minutes early, sign in and sit in the waiting room. No one acknowledged that my interviewer was running late until over 30 minutes past my time slot.
No apologies. Nothing. I was rushed through my interview in what felt like 5 minutes. No time for me to ask questions. Actually, when I asked questions, the interviewer didn't seem interested in answering them honestly. Made me feel like the only reason they called me was because I was a minority.
Downright, the rudest person I've ever interviewed with.