There are a total of four separate sessions:
1. Initial phone screen with recruiter. Basic Q&A, why are you interested, etc.
2. Hour-long conversation with hiring manager. Discussion-based. Goes in-depth into the team, what they are looking for, and your background.
3. Hour-long product case study. This threw me off. It is very product-focused.
4. Almost 3-hour technical screen for depth and breadth.