Inventory oversells after region partition
Your inventory service runs active-active across two regions with async bidirectional replication. After a 4-minute cross-region link partition at 03:00, you oversell: an item with 1 unit in stock got sold to two different customers. Dashboards: during the partition, region-A and region-B each independently decremented the same item's stock to 0; after the link healed, replication 'merged' and the count went negative; both regions accepted a checkout for the last unit. No deploy. How do you triage and mitigate?
What a strong answer looks like
Stop the bleeding first (mitigate), then form hypotheses from real signals. Separate root cause from symptom, communicate status as you go, and close with what prevents a repeat.
0:00 of about 45 min
Which questions mattered is sealed until you submit. Telling you now would just be handing over the edge cases.
Run or narrate your approach, then ask the coach.