I had an in-person interview set up through a third-party recruiter. I only interviewed with one person -- the direct supervisor for the position. He had set questions to ask me, which were very straightforward. The interview was mostly behavioral with general questions. It lasted 45 mins,

Informal, though they may do it differently each time. I had a 3-panel interview and was immediately notified within a couple of days that they wanted to move forward. As long as you are open to learning and can get along with the interviewers, you should be ok.