There were 3 parts to the interview process.

First was with the recruiter to know my background and prep me for the second interview. The second interview was a technical interview with the tech lead of the team. That interview was roughly an hour phone call touching across common back-end interview questions.

After that, they decided whether to bring you on campus for a final round interview. It was a roughly 6.5-hour interview, separated into individual sections that included lunch.

Question on hypothetical distributed system mathematics