Serverless cold start wave
Your image-resize endpoint runs on a serverless platform that scales to zero when idle and scales out one new instance per unit of concurrency. A marketing email goes out at 10:00 and within seconds thousands of users click through. Almost every one of those first requests takes 3–5s instead of the usual 150ms, and a chunk of them time out at the CDN. After ~30 seconds latency returns to normal. Logs show a flood of `init` / `coldstart` markers at 10:00:0x. There was no deploy. How do you triage and prevent the next email from doing this?
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 24 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.