Code RoomPrices missing despite HTTP 200
HardPrep Room Coding #2827

Prices missing despite HTTP 200

On-callDistributed systemsSenior–Staff~35 min

Your catalog service calls an upstream pricing service over HTTP. Starting 13:20, ~12% of product pages render with prices missing or showing $0.00, but your error rate is FLAT — no exceptions, no timeouts. Dashboards: the upstream returns HTTP 200 on the affected calls, but the response bodies are truncated or empty (your JSON parser silently yields a default-zero price rather than throwing). The upstream sits behind a load balancer that was reconfigured at 13:15 to add response buffering with a new max-body / idle-timeout setting. 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.