Discovery feed ranking
Your task
Design the ML-ranked feed for a short-video app with 200M DAU where the feed is pure discovery (not follow-based), every scroll picks the next best video from a 1B-video corpus. Optimize for watch-time and meaningful engagement, serve the next video in under 100ms, and incorporate integrity (don't over-amplify borderline/harmful content).
It covers
- Ml ranking
- Engagement
- Integrity