Got a phone screen with a recruiter after an employee referral. Afterwards, interviewed over the phone with three engineers on the team I was applying for; it was very casual and I felt invited to join in on their conversation about their current technology and what gaps they needed to fill on their expanding team. Then a (pretty large) coding challenge that took several days to complete, but wasn't unreasonable, and after that an onsite interview. The recruiter I interfaced with during the process was very responsive and helpful.
The onsite interview was fantastic, I wish more tech companies interviewed like they do. It consisted of 5 30-minute back-to-back interview sessions with 2-3 staff members of various disciplines (mostly engineers). They didn't bother with the usual/rather useless whiteboard coding challenges, instead each interview session was very behavioral in nature and gave great insight into the company culture and the team's main products. It was clear they wanted to get to know me as a person, and that it was a great fit on both sides (probably helps that I had a ton of prior relevant domain/tech experience at my previous job). Prior to the first interview session, a staff member voluntarily gave me a tour of the office. They made me feel at home, and gave me time to ask any questions I needed so long as each session wasn't running too far over time. One thing I'm glad I did prior to the interview was some homework on the company's products and each person I was to interview with that day.
Got an offer letter several days later directly from the company's VP of Engineering. Several staff members at Burlingame reached out to me that same day to answer any questions I had with initial onboarding. Overall an outstanding interview experience from the start, and easily the best onsite interview I've ever had my entire career.