I went through 2.5 rounds of interviews before deciding to pull out of my candidacy.
The first was a typical recruiter screen, then I met with the head of product and product strategy for an hour. This conversation was great and you could tell he knows product and that working for him would be both challenging and rewarding.
After that I was scheduled to meet with the engineering manager for 30 and then a 75 min case study with the head of product again.
I ended up taking the interview with the engineering manager and this is where things went south. This person asked some of the most detailed questions that without knowing the product inside and out would be impossible to answer further than generic responses. This person also asked about his own tech stack to me; as if I had experience working within the company and understanding or knowing the tech stack. He also at one point asked me to estimate how long a feature would take without any knowledge of the dev team, skill sets, other competing priorities, or the product it self. This person also gave off the impression that he was smarter than you and we didn't discuss how we could work together to create a great team.
It was at this point I decided to pull out of the candidacy because I knew we would not have the type of working relationship that is needed to form a good product/engineering team.
Of course no offer, but im not even sure I would take it if I made it all of that way even though the head of product was amazing and the mission is awesome.