Ship an LLM feature and the questions start: Is it fast? Is it reliable? Is it costing too much? Is quality drifting? LLM monitoring answers those questions on live traffic - and AI monitoring does it before users notice. Here's the playbook.
The metrics that matter
A good monitoring dashboard tracks a small set of high-signal metrics per model, provider, and token:
- Latency - average and P95, plus time-to-first-token for chat workloads.
- Error rate - 4xx, 5xx, and rate-limited requests as a percentage of total.
- Throughput - requests per period, so you can spot sudden spikes or drops.
- Cost - daily and monthly spend, burn rate, and average cost per request.
- Quality - evaluation scores over time, so you can catch drift early.
AI model monitoring vs. LLM monitoring
AI model monitoring is the broad discipline: watching any deployed model for performance, data drift, and cost. LLM monitoring zeroes in on generative models with token-based pricing and prompt-driven outputs. An ML observability platform that handles both will track latency and error rate like classic monitors, plus tokens, cost per call, and an LLM evaluation score - which classic tools simply can't compute.
Baselines first
You can't detect drift without a baseline. Before going live, record a week of healthy traffic: typical latency, error rate, cost per request, and quality scores. Then alert on meaningful deviations - not on every twitch.
# Example alert thresholds (tune to your traffic)
error_rate > 1% # page on call, check provider status
p95_latency > 3s # investigate routing and model load
cost_per_request > 2x baseline # check prompt bloat or model creep
quality_score < 0.85 # check recent prompt deployments
Monitoring through the whole lifecycle
LLM monitoring isn't just a dashboard - it's tied to deployment. In Infere, monitoring connects to prompt management: every deployment is a git commit, so when quality drifts, you can trace it to the exact prompt version and roll back in one click. That link between observability and prompt git is what separates monitoring from firefighting.
The best LLM monitoring makes the cause of a regression obvious, not just the symptom.
Wrapping up
LLM monitoring, AI observability, and prompt management are three parts of the same system. Infere unifies them: route traffic, watch latency and cost, evaluate quality, and roll back prompt changes - all from one OpenAI-compatible platform.
Cost is one of the key metrics to monitor - our true cost of agentic coding breakdown shows where spend actually goes across tools like Claude Code, Codex, and Cursor. For a deeper look at the observability layer behind monitoring, read our LLM observability guide.