It was one long interview. I first spoke with the head of HR and then the CEO (I was going to be her assistant). After the head of HR and the CEO spoke with me for about an hour in total I spoke with every employee that worked in the office.
Each employee talked with me for about 15 minutes, and it seemed as though most of them did not know they were going to speak with me, so it was a surprise for most of them. This process lasted another 2 hours, as I talked to 10 people for about 10-15 minutes each.