Entire interview process took about 2 months consisting of 1 recruiter phone screen, a video interview with another PM in the group, a video interview with the hiring manager, 3-4 video interviews with engineering, and another round of Zoom interviews with other PMs in the group.
The initial screening interviews were a blend of behavioral questions related to my prior work experience and thought experiments on how to apply prior learnings to the core TikTok product feature in question. The interviewers had specific case interview-style questions on decision-making using product sense/data/prior body of work. I had the general sense that they had many potential projects in the pipeline due to the specific nature of some questions and their curiosity in how I'd approach what seemed to be actual situations they were facing in real time.
Overall it was definitely one of the more challenging interview processes, but it was helped along by being open about expectations and the genuine excitement about the platform's momentum I felt from all the interviewers. I had multiple other interview rounds with other companies occurring at the same time with different deadlines, and the recruiting coordinator here really helped figure out how to best navigate timelines as TikTok was my first choice.