There was a screening interview with HR, then 1:1 phone interviews with eleven different people. All were scheduled individually. One person requested an in person interview after our phone interview and the in person interview was over breakfast and lasted three hours. Mostly that interviewer wanted to make sure I knew the market. The interviewers all had to fill out a form and recomend me for the job so I could go on to the next level.
I prepared for at least an hour prior to each interview.