You get called in to schedule interview. I interviewed on campus for about 45 mins to 1 hour. The entire thing was behavioral. "Tell me about a time when you faced this challenge and what did you do etc...". Talked about current projects and struggles in college. They take lots of notes about how you respond. They want to see how you explain technical things in a way as to not lose the attention of the listener. Presentation is key. If you make it past the initial interview, someone (usually your future boss) will call you for an on site interview. Someone from your future group takes you to breakfast and takes you from interview to interview. You meet with about 5 or 6 people who talk to you informally really just to see what your personality is like. The usual "what do you like to do" and "tell me about yourself". The 2nd interview step is easier than the on-campus 1st step. If you are a new-hire, they might give you an offer at the end of the day (on-site). If you are an experienced hire, they might wait to inform you later on. Usually everybody gets together at the end of the day to discuss their opinions of the candidate.