Routing changes led to a major multi-hour outage impacting Facebook, Instagram, and WhatsApp.
What Happened
Facebook/Meta Service Outage (2021) became a widely discussed incident because its impact reached critical business and customer workflows across industries.
Operational Impact
From service disruption to response overhead, this event highlights why dependency awareness, strong release controls, and tested runbooks are essential.
Key Lessons
- Protect critical DNS/BGP workflows
- Add independent recovery channels
- Continuously test failover plans
Implementation Guidance
Teams should translate these lessons into engineering standards: staged rollouts, stronger observability, clear ownership, and periodic resilience drills.
