I was referred by a Genentech employee and had a hour phone interview that included a 20 min presentation (I sent the slides in advance). The on-site interview was a full day (8:00am-5:00pm) and included 13 back to back 30min, one-on-one interviews. The day included my 1-hour seminar, which is known to be the most important part of the day. Additionally, lunch is a sandwich that you are supposed to eat during a round-table session. This round-table is a discussion among 15-20 scientists from different disciplines, but it feels more like a continuous stream of questions from everyone. Personally, I think it is a very fruitful part of the interview and it shouldn't be separated from lunch for the sake of the candidate.