Single interviewer on site, the hiring manager. Process was a bit rushed and the correct room wasn't booked, so we ended up having to move halfway through the process. The interview started off friendly, but eventually went downhill with the manager challenging my qualifications and discounting my experience. By the end, I could tell he was not someone I would want to work with (too intense, no leadership skills), nor was the culture going to be a good fit. It's too bad there were no peer interviews, as they might have changed my mind.