Code Room
On-callMedium
Question
A cache-heavy service's latency is creeping up and its hit rate is dropping, even though traffic is steady. You suspect the cache is evicting useful data. How do you investigate?
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.
Learn the concepts
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Run or narrate your approach, then ask the coach.