Be on your A game but don't overdress. It's spacex so the rule of cool applies. Know your topics and don't talk too much. This is the cream of the crop you're dealing with. If you're lucky they will give you a tour of the launch pads.

In depth. Demanding and eye opening. The interviewer asked a lot of questions that I have never been asked before. The interviewers were intellectual and easy to talk to. All of my questions were answered by the interviewers.