... step-by-step way to solve a problem. Which means every algorithm has a job: Example (TikTok): the job is matchmaking - pairing a video with someone who ll care. Success = full completions + replays. Translation: design for finish-ability and rewatch-ability. Example (Instagram): there isn t one master algorithm. Feed, Explore, and Reels each have different goals. Reels cares about watch time and share-ability, so you need to think about % of view completion and getting shared in DMs. This ...