LLM Observability and Tracing: Seeing What the Model Actually Did

LLM systems fail in ways traditional apps do not.

Without traces, you cannot diagnose drift, latency, or hallucinations.

Log prompts, retrieval results, tool calls, and outputs.

Include latency and cost metrics for each step.

Remove sensitive data before logging.

Use role-based access to limit who can view traces.

Set alerts for spikes in latency or refusal rates.

Detect abnormal output patterns early to prevent regressions.

Build dashboards that correlate failures with retrieval or tool errors.

Use replay tools to reproduce issues with real inputs.

Sample traces by risk level so critical flows are fully captured.

Use adaptive sampling that increases coverage during incidents.

Keep deterministic sampling keys to compare runs over time.

Capture a small always-on baseline for long-term trend analysis.

Log trace coverage so gaps are visible to on-call teams.

Use redaction at the edge to reduce sensitive data exposure.

Store sampling rules in version control for auditability.

Balance sample rates with storage budgets and compliance limits.

Propagate trace IDs across retrieval, tools, and model calls.

Link user sessions to traces to debug end-to-end journeys.

Tag traces with model versions to isolate regressions quickly.

Correlate cost metrics to trace spans for budgeting visibility.

Add span annotations for policy decisions and overrides.

Use timeline views to identify bottlenecks across stages.

Store minimal breadcrumbs for low-risk flows to save cost.

Provide self-serve trace lookup for support teams.

Add retention tiers so high-value traces live longer.

Index traces by feature flag state to compare rollouts.

Capture retry counts to expose hidden reliability issues.

Link traces to incident tickets for faster investigations.

Record cache hit markers to understand retrieval efficiency.

Include tool version tags when tool results change unexpectedly.

Is full logging required? Not always; sample and prioritize high-risk flows.

Does logging increase cost? Yes, but it saves time in debugging.

What is the quickest win? Log retrieval inputs and outputs first.