8bit.tr Journal
Cost Observability for LLMs: Unit Economics at Token Level
How to track per-token costs, margin, and efficiency across LLM workloads.
Why Cost Observability Matters
LLM costs scale linearly with usage.
Without visibility, margins can disappear quickly.
Per-Token Accounting
Track input and output tokens by workflow.
Allocate costs to teams, tenants, or features.
Efficiency Metrics
Measure cost per successful task and per user session.
Use these metrics to guide optimization priorities.
Budget Enforcement
Set budgets per tenant or feature.
Trigger alerts when usage exceeds thresholds.
Optimization Levers
Summarization, routing, and caching reduce token usage.
Track ROI to validate cost-saving efforts.
Cost Allocation
Tag costs by team, product, and customer tier.
Include infrastructure overhead in unit cost calculations.
Track shared services like retrieval and vector storage separately.
Report cost per feature to reveal hidden expensive paths.
Set internal chargeback rates to drive accountability.
Publish monthly cost summaries for leadership review.
Compare forecasted versus actual costs to catch surprises.
Track cost anomalies with automated alerts.
Cost Governance
Define cost budgets alongside performance budgets.
Require approvals for large cost-driving changes.
Use cost guardrails in CI to flag expensive regressions.
Track unit economics by region to spot outliers.
Review vendor price changes for budget impacts.
Prioritize savings that do not harm quality.
Add cost annotations in runbooks for on-call teams.
Include cost metrics in product OKRs.
Set monthly cost targets per product line.
Review the top cost drivers each sprint for quick wins.
Link cost spikes to feature flags for faster rollback.
Maintain a cost incident process for major overruns.
Track cost per user cohort to compare performance.
Align cost governance with procurement and finance reviews.
Expose cost dashboards to product owners for visibility.
Benchmark costs against previous releases to spot drift.
Set alerts for sudden cost-per-request spikes.
Track unit cost by model tier to guide routing decisions.
FAQ: Cost Observability
Is per-token tracking enough? It is a start, but add latency and quality metrics.
What is the fastest win? Track top 5 most expensive workflows.
What is the biggest risk? Cost optimizations that degrade quality.
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