Expect exams. On the computer, math, logic, and critical thinking followed by personality exams. They seem to value about 40-60 the exams to the actual interview. Mostly common sense stuff, but can be difficult if you weren't expecting it. Just shoot to answer accurately and skip if you don't know for sure. I definitely know people who've bombed it but been hired because they were just a pleasure to work with, so don't stress and just focus on what's important-- being diligent and hard working.
I first interviewed with an acquisition agent, then with the CEO himself because I guess I did well enough on the exams and they liked me. Once Sean got a chance to speak with me, I was on-board the following Monday. Literally interviewed Friday, started the following Monday.