DNS split-brain after resolver migration
Half your fleet suddenly can't reach an internal service db-primary.internal. Affected pods log 'no such host' / NXDOMAIN; the other half resolve it fine. Dashboards: error rate on the orders API is ~50% and bouncing; the unaffected half of pods are healthy. Recent context: 20 minutes ago an infra change migrated internal DNS from a self-hosted CoreDNS to a managed resolver, and someone also bumped record TTLs from 30s to 3600s last week. No application 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 35 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.