2 interviews in one day. First was Manager, then Director. Immediately get offered on the same day. Received offer letter and medical check up on the interview day too.

Original process was single person when I was hired. Later it became multiple one-on-one interviews, with most of the group members being interviewers. I was a participant in that process too. Unfortunately, when all voted "No" on a candidate, the engineering director decided to hire the individual anyway, and make him the manager of the group.