Friend Bubbles: Enhancing Social Discovery on Facebook Reels

Introduced 'Friend Bubbles' to Facebook Reels, a system that highlights content friends have liked or reacted to. This involved developing user-user closeness models (survey-based and on-platform interaction-based) to identify relevant friends, and enhancing video ranking models with friend-bubble interaction signals and new tasks to incorporate relationship strength and learn downstream engagement. The system also optimized client-side performance by integrating friend-bubble metadata retrieval into the existing video prefetch work and conditionally disabling animations to maintain smooth scrolling and low latency.