How we scale Live streaming for millions of viewers simultaneously

This post details Meta's significant advancements in scaling live streaming infrastructure to support millions of concurrent viewers for both user-generated content and professional broadcasts. It highlights the development of new ingestion capabilities with built-in redundancy and failover mechanisms, the scaling of delivery infrastructure to combat the 'thundering herd problem' through request coalescing and cache sharding, and proactive collaboration with ISPs to manage network congestion. The post also outlines future challenges and explorations, such as using LTE-Broadcast for last-mile delivery and the need to optimize for a high volume of simultaneous smaller-reach streams during events like New Year's Eve.