1. Typical recruiter interview
2. Tech questions with Head of (i forget, maybe of hiring?)
3. paired programming DSA questions
4. Onsite or virtual onsite with tech, behavioral, system design and whiteboarding
Honestly, this interview process is typical for FANG positions but not some random startup but I guess thats just the job market these days. They're just purposefully making it difficult and trying to get some kind of unicorn candidate.
Also the interviewers seemed absolutely miserable. So take that as a warning.