The interview consisted of four 1-hour interviews with 4 people, with lunch in between. The interviewers were very courteous and helpful in keeping a low stress environment and answering questions. Some difficult questions were asked, some of which I didn't know the answers to, but they made it clear that I shouldn't stress over not being able to answer all questions. I believe that my preparation allowed me to answer most of the questions and is what got me the job.