Ten people? 10?! I guess if it's really 5 slots with 2 interviewers (though that has its own set of disadvantages, on both sides), I guess. But, that just sounds like a distressingly long day.
It was, 5 meetings including lunch. Each meeting had at least 2 interviewers and I had lunch with my prospective manager and another senior peer.
1. 2 pms - collab and project management questions.
2. Trivia Q&A with 2 devs and tech projects
3. Lunch with Dir. Eng, and senior dev.
4. Whiteboard leetcode with A researcher and a junior dev.
5. Systems design with Dir. Eng and a senior devops
6. Chat sessionr for questions with VP of Eng.
Needles to say I was burn out on the systems interview after having been in interviewing mode all day and the interviewers were definitely mentally drained, nitpicking on a lot of low leve elements on a systems design task.