Two technical screens, followed by actual on-sites. The offices are beautiful, and they give you some swag for coming on-site.

They ask "practical" problems, not really LeetCode style, but not necessarily realistic either. The problems aren't necessarily hard, but my advice is to go with the simplest solution, as you've got no guarantee that your interviewers will understand anything beyond that. My first interviewers seemed absolutely baffled by the idea of a completion handler function, so a lot of time was lost trying to explain to them how that would work, before changing to a simple user-polling approach.

Given a basic API for a low-level disk drive, implement a file system that can read and write.