Only had one face to face interview that lasted about an hour. Just general questions as to your previous experiences and academic career. There is a standard reasoning test.

Only went to one 2 hour long group/panel interview after passing a phone screen. First, with a current deployment engineer and a member of the development department. Then, with the manager I would be reporting to. My interviewers were insightful, professional, and sincere. I was asked about my undergraduate experience and involvement in recent projects. Got an offer 2 weeks later. The background check took almost 3 weeks.