Incidents
Something is broken, and you're on call. Read the logs, pick the fix, and watch the system come back to life. Every component links to the lesson that explains it.
- Step by stepSystem Design (Beginner)4 components
Black Friday outage
Checkout is down in the middle of a sale. Fix four failures, one hop at a time, and get traffic flowing again.
- System mapSystem Design (Beginner)10 components
Bring the store back online
Ten systems behind an online store are down. Fix them in any order, then see what shoppers can actually do.
- Step by stepSystem Design (Beginner)4 components
Kafka consumer lag
Order events are piling up and confirmations are hours late. Trace the lag from producer to consumer and fix four causes.
- System mapAI Engineering8 components
The HR chatbot gives wrong answers
A RAG chatbot answers HR questions badly. Fix eight parts of its pipeline, then see which answers employees can trust.