Field Guide

Your token spend is up. Do you know what it's producing?

Three outcome signals tell you whether AI is earning its cost. Eleven guardrail metrics tell you whether the program is being run well. Learn what to track, what each signal tells you, and what to do next.

Faros guide cover: Measuring token efficiency in AI engineering, with 14 metrics to track and apply.

This is what unmanaged token spend looks like

Faros runs diagnostics on AI-enabled SDLCs. These patterns show up consistently once the right signals are connected:

Misaligned tokens

80% of token spend falls outside top business initiatives

Wasteful tokens

30% of token spend produces no useful outcome

Mispriced tokens

Most teams are paying 3x for work a cheaper model handles just as well

The benefits

What this guide gives you

Three decisions you will be able to make with data, not gut feel.

  • Where to redirect token spend toward work that matters
    Find it, quantify it, and shift it toward initiatives that move the business
  • Where to stop paying for sessions that produce nothing
    Wasteful token spend concentrates in specific repos, teams, and types of work. This guide shows you where.
  • Which tools and models to keep, scope, or cut
    Normalized cost-per-output metrics make vendor and model decisions defensible.
Piles of AI tokens, being directed to a target
The full picture

14 metrics across four categories

Based on two years of telemetry from 22,000 developers across 4,000 teams.

Outcomes

3 Metrics

Connect token spend to shipped work, strategic priorities, and defensible ROI.

  • Productive vs. wasteful token spend
  • Token spend by tool, normalized to output
  • Alignment of spend to strategic work

Adoption

4 Metrics

Know which tools are earning their licenses and which have become shelfware.

  • License utilization rate
  • Usage depth distribution
  • Tool preference relative to licenses
  • Code acceptance rate by tool

Productivity

3 Metrics

Find where AI is accelerating output and where it is creating new bottlenecks.

  • PR merge rate per developer by tool
  • Cycle time by stage
  • Lead time from commit to production

quality

4 Metrics

Instrument the signals that surveys miss before problems compound in production.

  • Bugs per developer, trended
  • Incidents per PR, trended
  • PRs merged without any review
  • AI risk footprint by repo
Graduation cap with a tassel over a dark gradient background.
Read the guide

Get the Field Guide to Measuring Token Efficiency

14 metrics to track, what they tell you, and how to use them