I had several technical phone screens involving completing problems that were a good level of difficulty. I was able to complete or nearly complete all of them, but didn't have loads of time left over. I appreciated being able to talk with several different people on the engineering team.
After the phone screens, I did an all day onsite in San Francisco. This involved completing a small project, and presenting that to a small group. After that, I had two more short technical problems to solve and a discussion with a founder. Overall it was a very pleasant experience.