The interview process consisted of an initial phone call with a recruiter, a brief technical call with the hiring manager, a longer technical call with the entire core team, and an on site interview that lasted about 4.5 hours including lunch. The entire process took about 2-3 weeks total.
I am out of state from the Irvine office so they flew me out for the in person interview, gave me a rental car, hotel, etc. They made it as painless as possible all around.
The technical interviews were very straightforward -- fairly broad range, rapid fire technical questions trying to gauge your experience in various technologies and the depth of your knowledge. Lots of questions about the Linux OS and hardware interaction (how does memory work, CPU scheduling, etc.) and your knowledge on debugging issues in Linux. The in person interview consisted of back to back meetings with various teams you would work with, your direct team, and then the hiring manager and IT director. The interviews with other teams were a lot of behavioral questions and a few hypothetical scenarios you verbally walk through with them. The interview with the core team itself was mostly technical questions or questions about your experience from your previous employment and/or things you listed on your resume.
Finally the end of the afternoon they took me to lunch and it's more of an open ended discussion with the hiring manager and IT director where they talk about the job specifically, the company as a whole, and you can ask anything you want. Everyone was very friendly; they gave a tour of the campus which was really cool to see. The whole experience was great end to end!