Evaluation methods
1Metric-based
Fast, repeatable regression checks
Examples
Exact match / string match Executable tests (e.g. SQL) Might miss nuance
Combine with human or
model review 2Human
Expert judgment and calibration
Examples
Rank answers or score 1–5 Challenges
Slow · costly · reviewer disagreement Make it reliable
Refine the scorecard through review Show examples of score levels Set a pass/fail threshold 3LLM-as-a-judge
Model graders · scalable judgment
Single answer
Score against
rubric
Reference-guided
Compare to
gold answer
Challenges → Recommendations
Position biasSwap answer order Verbosity biasControl answer length Unreliable judgmentsValidate against human labels Make it reliable
Clear rubric · assessment before score Prefer pairwise or pass/fail when suitable - Human-labeled
examples - Validate a
capable judge - Consistent
human agreement - Scale, then
optimize cost
Combine methods. Calibrate with humans. Scale what works.
Design your eval process
1Define eval
objective
What does success look like?
2Collect
dataset
Examples that reflect real use
3Define eval
metrics
How will you measure success?
4Run and
compare evals
Iterate and improve
5Continuously
evaluate
Evaluate changes and new cases
Run evals
Establish a baseline
Inspect failures
Find what needs improving
Make a change
Prompt, model, tools or retrieval
Rerun evals
Use the same test dataset
Compare results
Improvements and regressions
1Trigger
Manual
Slack Mention / DM
Delegate a Linear task
Start in CodexAutomatic
Rising Sentry errors
Completed Experiments
(Code Cleanup)
2Execution
Environment
Dedicated server per engineer Isolated sandbox per task Mobile simulatorRepositories
GitHub
GitLab
3Validation
Depending on the task, different validation methods may be relevant.
Automated tests & CI
Run relevant tests and pass CI checks.
Visual validation
Agent checks in a simulator or browser. Human testing when needed.
Evals
Compare costs, quality and tool-call precision / recall.
Code review
Address CodeRabbit and engineer feedback, then rerun checks.
4Shipping
Release safeguards
ArgoProgressive rolloutCanary · metric checks · rollback
GrowthBookA/B ExperimentsFeature flags · guardrail metrics
AI + Engineers
How the way we build software changed