Flapping partition leadership
Your Kafka-style streaming cluster (and its coordination layer) sits across three AZs. Starting 02:15 you get intermittent connectivity loss between one AZ and the other two — packets drop for 10–30 seconds, recover, then drop again (a flapping partition, not a clean cut). Dashboards: leader elections are firing repeatedly; partition leadership keeps moving; consumer lag oscillates wildly; producer error rate spikes during each flap. CPU/disk are fine. Recent context: a cloud-provider networking incident is in progress for that AZ. 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.