Applied for and was invited to a general on-campus interview with two employees. Very simple, just talking about my background, etc.
Two weeks later, I was invited to a superday with three 30-minute interviews. They were mostly generic HR questions, with each pair of employees making sure not to ask questions from earlier groups. As a technology intern, I was also asked to do a very simple coding exercise on a piece of paper. Overall it was rather straightforward and direct, though I didn't exactly feel confident walking out of the building.
A few days after that I was invited to a second onsite for a different department/location. This consisted of just two 30-minute interviews, which were much more relaxed and conversational than the first office. It felt less like a Q&A session and more like a casual conversation with employees.
But in the end, the second onsite didn't even matter - the very next day, my recruiter called me and said that the first location wanted to extend an offer. I never heard back about the second office.