Out of the panel interviewers, 1 was a student, 1 was a retired prof, and 1 was an MD. I stressed about the panel interview, and it felt awkward to me.
Afterwords, I thought I would be rejected for my poor performance. I wish I knew not to worry so much if you have a bad experience in the panel, as I somehow was accepted. Just be yourself and try to stay calm.
Also, another thing that would be useful to know beforehand is that at the beginning of the panel, we were asked to "say something about oursleves". Bring up topics you want them to ask you about in the interview.
Study the SDN questions, as we weren't asked any hypothetical questions or odd questions that were not already described on SDN feedback.