Phone screen with recruiter -> phone screen with the hiring manager -> 4-hour in-person interview with other Technical Product Managers (TPM's), technical lead, hiring managers. They were at least very transparent about the fact that you have to study for a long, difficult exam for the first 2 months of employment to be certified in their product, and if you fail, you're out. Zippo. Appreciated the clarity.
But, on to the interview process! It went really well until the in-person part, which was, from an interviewee perspective, quite awkward from the start.
TPMs: The "product exercise" (here's a problem, solve it by coming up with an idea for a mock product) was very, very awkward; asking questions to try to narrow down a target market and/or find out why we were exploring that option in the first place just got shrugs from the interviewers. Zero actual, collaborative engagement. Maybe that's just how they do things, which is the opposite of literally any other similar exercise I've ever done, but it seemed like a "sink or swim" vibe, heavily leaning towards the bottom of the lake. They then proceeded to ask questions off a script about my experience - albeit none about taking an actual product to market, strangely enough (this was listed as a reason for denial). Noticed the ol' "stretch-and-sigh" when I asked a question about their experience at the company as a PM. (Isn't that what you're there for?)
Tech lead: Very personable and clearly knowledgeable both about the company and the product. Talked to him for the shortest amount of time of the group, unfortunately, but if all the engineers at Relativity are of that caliber, they're doing something right.
Hiring managers: I'd give this one a 50/50. Went pretty well, with some good discussion around the position and expectations; how they actually "get stuff done" etc. etc., until they started asking for the names of every manager I've ever had (spelled out exactly). Maybe I've just had relatively tame interviewers in the past, but I found this to be quite uncomfortable. It was totally scripted, and ultimately struck me as though they were just gathering professional data for future use, rather than using the time to get to know me and my actual fit for the position. When I asked them about it (after their asking for a 5th person's first and last name), essentially to A) know if I should expect my current manager to be contacted, which is quite unprofessional, and B) simply understand their logic, the atmosphere in the room shifted straight to awkward.
Finally, recruiter took me on a quick tour of the office, and basically alluded to the CEO being god's gift to the title for most of the time. Was a little strange, but hey, at least everybody doesn't hate him.
Had a pretty awkward feedback call with the recruiter a few days later informing me of their decision, citing reasons that weren't asked about in the interview for the rejection. Strangely enough, I was told that culture-wise, it seemed to be a great fit, and this was something they had made seem incredibly important from the very first recruiter phone screen. Oh well!
All said and done, didn't get an offer, and maybe I did just have a bad experience, get stuck with specific people on a bad day, or fall victim to some other cosmic force, but it could have been much, much worse. Other fish in the sea. YMMV.