Heard about the role through a recruiter. The recruiter was pleasant, and after a couple of weeks, I received a request to apply formally for the role. Another few days and the first round was scheduled. I felt good vibes from the first round, and the second round was scheduled. The second round was a relatively easy algorithm/live coding challenge. I liked that guy as well.
For the third round, it was a whiteboard/systems design challenge, which I felt confident in. Then a product design interview immediately afterwards. The product design interview was performed by a junior engineer whose questions weren't clear. After a few days, the feedback was that I had 1 minor flaw in my system design (which, if he'd asked, I would have explained the difference between an iterator and an array in the selected database) and that the product interview didn't contain enough new ideas.
It seems like a junior engineer with 3 years of experience isn't the best judge of the skillset of 10+ years of experience. It's unfortunate to have spent so much time interviewing only to be assessed by someone who doesn't have the skills to evaluate experience. I usually have an attitude of wanting to learn something from the interviewers. This turns out to have just been a waste of time.