The interview was three hours long, separated into six groups of interviewers, 30 minutes each, with one to two people in each group for a total of about 10 people. I started out meeting the hiring manager and he briefly explained how the process was going to go. Gave me some tips for the interviews and left. A couple groups composing of engineers and managers from higher levels asked questions and got to know me. Mostly explained what I did at my current job and how it can apply to this one. Then the hiring manager came back for a full 30 minute talk. His portion was not an interview, but a chance to give advice on what to say in the following interviews and how to construct them properly, and gave me opportunities to ask questions and apply my work experience into these interviews. I have to say, I've never had an interview where the hiring manager gave me tips to succeed, so I was very surprised yet grateful for that. The next few groups of interviews were more engineers and technicians/technologists that I would work around every day, and were more there to get a feel for me and how I work. They explained day to day operations and gave me a quick tour of one area similar to where I would work. They were all very professional and friendly. Initially, I was overwhelmed when I heard how long the interview would be and how many people I'd be talking to. But the questions were pretty straightforward; I did get a little repetitive at times, because it got hard to keep track of who I told what things to already.