“At TikTok, the company organizes all the videos its users post into a web of clusters, sorted by topics, the former TikTok employees said. The clusters span the universe of TikTok videos, including ones named: mainstream female, alt female, southeastern black male, and coastal, white-collar male. Each cluster includes subgroups; for alt female, those included tattoos, some lesbian content, and “Portland.” A cluster about professional basketball, for example, had subgroups about the Golden State Warriors, and star player Steph Curry. TikTok tracked the categories of content and users on its app in an effort to understand trends and find ways to boost engagement, some of the former employees said. Some TikTok employees could view the unique identification numbers of the users associated with each cluster, as well as the list of users who were watching videos in each cluster. Additionally, employees could look up users based on their ID number—a series of numbers each TikTok user is given when they start watching videos on the app—to see what cluster they were associated with, according to some of the former employees.”

Source : TikTok Tracked Users Who Watched Gay Content, Prompting Employee Complaints – WSJ