Why Hidden Failures Will Crash Your LLM Service, A Practitioner's Observability Playbook
LLM services can look healthy in traditional APM while silently hallucinating, truncating or drifting in quality. The guide breaks down four production failure classes—quality drift, prompt failures, cost spikes, latency degradation—and shows concrete logging, token-usage metrics, finish‑reason flags and hybrid rule‑plus‑model evaluation to surface them. Implementing these signals turns invisible bugs into actionable alerts.