I meet with 7 engineers and scientists over the course of the day (5-6 hours). I had a group of 2 scientists interview panel style, I meet with my potential direct boss 1:1, I meet with a senior VP 1:1, and finally meet with HR 1:1. I was taken out to lunch with about 6 engineers and scientists and we got to get to know one another over the course of the meal. The company was very young at the time and the process is not like that now. No on takes you to lunch and you just interview in the same room and engineers come in at their allotted times.