I only had one interview and it was very standard in terms of questions, nothing out of the blue or unexpectedly challenging. I interviewed with the two people who will be supervisors of the position I interviewed for; I emailed with HR but did not interview with them. They were very nice and the interview was genuinely enjoyable! The hiring process was extremely quick. I heard back about from my application within about one week, and from the day I received that first email to receiving an offer was only 10 days. Everyone I have spoken to is very pleasant and friendly! I would guess the exact interview process changes a bit depending on the imprint your position is within.