Co-experiences: Hanging out in the digital living room

What this post added

This post details the development of 'co-experiences', specifically focusing on the 'Watch Together' feature. It introduces a new state synchronization platform ('state sync') built on top of existing multiway infrastructure to handle real-time synchronization of playback controls and audio streams across devices for synchronous viewing. The platform uses Thrift for defining message structures and operates in three parts: subscription, input (snapshot-based model), and resolution (centralized server-side resolver). This platform is designed to be generic and is already powering other features like screen-sharing moderation in Messenger Rooms and Rooms to Live, and supports cross-app communication.