System Design Twitter Course

Lesson 50: Automated Incident Response

What We’re Building Today

You’ve built monitoring and alerting in Lesson 49. Now we’re building the system that responds automatically when things go wrong. By the end of this lesson, you’ll have an incident response system that:

Detects failures automatically from monitoring alerts

Executes smart remediation actions (restart, scale, rollback)

Escalates to humans only when automation can’t fix it

Tracks everything for post-incident learning

Reduces Mean Time To Recovery (MTTR) from 20 minutes to 4 minutes

Real-World Context: When AWS has an outage, automated systems try dozens of fixes before paging engineers. Netflix’s Chaos Kong can take down entire AWS regions, and automated systems restore service. We’re building that capability today.