Etcd cluster writes failing
Your config service is backed by a 5-node etcd cluster across 3 AZs (2/2/1). At 04:00 all writes start failing with 'no leader' / context-deadline-exceeded, though reads still work. Dashboards: an AZ hosting 2 etcd nodes lost network at 03:58; the remaining cluster has 3 of 5 nodes; leader elections are flapping; raft proposals time out; clients that need to WRITE config are blocked. The 2-node AZ isn't coming back soon. 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.