Retry amplification cascades through hops
A user-facing request fans out through 4 service hops (gateway → A → B → C). At 17:10 you see massive load on service C and timeouts at the gateway. Dashboards: each hop has its own 2s timeout and retries twice on timeout; C's actual p99 is 1.8s but it's receiving ~8x its normal request volume; user traffic is flat; the gateway's own deadline is 2s. A latency bump on C started at 17:05 (a slow query). 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 40 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.