I had 3 separate interviews, a phone interview with HR, one with the Manager and one with the Director. I then had to fill out references where they asked all of them a series of questions.

Typical interview process, with a phone screen and then 3 additional interviews. When HR reached out for an initial phone call with a director, I thought it was just that - an informal phone call. However it turned out to be one of the actual interviews and was caught off guard. Luckily the interview itself was pretty casual with lots of questions being asked.