The process moved very fast: Phone screen, virtual onsite (4 rounds) in the next week. One week later had another call with a director. Each round is 45 minutes.
Everyone I talked to were very knowledgable, kind, and humble. I felt like that we were discussing how to solve problems in our day to day work. They kindly asked me to use my favorite programming language to solve the problem, and provided hints when I got stuck.
I also would like to say thanks for the recruiter. She is one of the most nice technical recruiter I had ever talked to.