Every department has its own hiring style, this process only applies to my own experience with product excellence engineer role. Had a phone screen with recruiter, then recruiter scheduled a 30 min phone interview with hiring manager. The hiring manager was more interested in finding out who you are rather than what you can do. Behavior questions and some none job related personal ones. There was no technical question, which was a bit of surprise. One week after, received a notice from recruiter I was rejected, they have enough junior engineers in their group and want more experienced ones. For people who do not know what Tesla Motors is, they will assume it was a badly organised company if they did the interview, even recruiter cares more technical aspect than the hiring manager.

Panel Interview with many managers and director. Went into a conference room inside the factory, so it was quite loud, it was in a busy area so there was a lot of distraction. I think this was intentional to keep you off guard. 3 hours of interviews in total, everyone was very nice.