Cache misses from nonexistent products
Starting at 22:45, your API's cache-hit ratio is normal at 88% but the origin database load has quietly doubled and a specific set of product-lookup endpoints is slow. Logs show a flood of requests for product IDs that don't exist (random-looking integers), each one a cache miss that falls through to a DB query returning no rows. The traffic is coming from a wide spread of IPs. No deploy happened. 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.