Screen call with HR followed by a short call with an engineer on the team I would be working for. Finally, a 3 hr long interview with the hiring manager and 3 other team members.

Initial phone screen interview, im an electrical engineer, so the basic screen was about very simple circuits 1 or 2 questions, don't be worried about this. Next part was about an hour long review of my resume with my potential hiring manager, and this was much more in-depth. You should really be confident about your resume and work experience and be able to explain it competently. The last part was an onsite interview to Seattle, which was amazing, they pay for everything and they really set you up nicely. The on-site interview was the most technical interview I have ever done and it was extremely rigorous and long (about 5 hours). With emphasis on an intial hour technical presentation + Q/A. Then 4-5 30 minute 1 on 1 interviews. They take you out to lunch which is nice as well. I think overall the technical on-site does not need to be too stressful, just make sure your presentation is good and that you spend a lot of time developing it. No one is trying to grill you, just trying to make sure you're a good fit.