Welcome to your interview.
The question is on your right: Design a Personalized Recommendation Ranker. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
You are designing a recommendation system for a consumer app that surfaces personalized suggestions from a large catalog. Users can express preferences through taps, skips, saves, and explicit settings, and the product team wants the ranking to adapt as those signals change.
Given a set of user preferences, how would you optimize recommendations?