DNS resolution fails
A service suddenly can't reach one of its dependencies. The logs show 'no such host' / name-resolution errors when it tries to call that dependency's hostname, while calls to other dependencies work fine. The dependency itself is up and reachable from a teammate's laptop by hostname. Your service didn't deploy. How do you triage this resolution failure?
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 20 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.