I was contacted to do a 1:1 interview on-campus after dropping my resume off at a career fair. This interview lasted 1/2 an hour and was mostly informational. After this interview, I was invited to the superday. The night before the superday, the company hosts a meet and greet style event at the hotel. Some of the superday interviewers are there. You will be told who you are interviewing with at this event, so if they are there it is a good idea to try to meet them. The next day is the superday. It consisted of three 1:1 interviews for half an hour each. It was mostly going over my resume and talking about past projects and classes. There were no overly technical questions.