Very thorough process. Began with a phone call from HR with just basic interview questions, followed by an on-site interview with several of the people I'll be working with. The first on-site interview consisted of three separate interviews with 2 people each. The second on-site interview were a series of one on one's with other people I'd be working with, with a lunch with my future boss. Everyone was very nice and the Mentor HR recruiter really helped prepare me for all of the interviews.