Engineering

Evaluating LLM extraction at production scale

Extracting structured data from conversations is easy to demo and hard to keep accurate. This is the evaluation loop that keeps our field accuracy above 97%.

CXCXAstra teamJul 28, 2026 · 5 min read

Language models are remarkably good at pulling structure out of messy conversations. They are also quietly inconsistent. A prompt change, a model update or a new customer vocabulary can cut accuracy without anyone noticing — until a rep sees a wrong next step on a deal.

Golden sets per field

We maintain hand-labelled evaluation sets for every field we extract, such as next steps, stakeholders, competitors and budget signals. Each set mixes typical examples with hard cases: sarcasm, hypotheticals (“if we had budget…”), multiple speakers and switching languages. Every change to a prompt or model runs against these sets before it ships.

Measure what users feel

Overall accuracy hides the errors that matter. We track precision and recall separately per field, because a false commitment is worse than a missed one. We also weight errors by impact: getting a close date wrong matters more than misspelling a job title.

“An extraction that’s confidently wrong does more damage than one that admits it isn’t sure.”

Drift alarms in production

  • Sample a slice of production extractions daily for human review.
  • Alert when confidence distributions or extraction rates shift sharply.
  • Treat every user correction as a labelled example and feed it back into the golden sets.
  • Pin model versions and roll out upgrades behind a comparison gate.

Calibrated confidence

Every extracted claim carries a confidence score, and we calibrate those scores so 90% really means right about nine times in ten. Low-confidence claims are shown as suggestions for a person to confirm rather than facts. That one design choice does more for user trust than any accuracy improvement.

Key takeaways
01Keep hand-labelled golden sets per field, including hard edge cases.
02Track precision and recall separately and weight errors by impact.
03Monitor drift in production and calibrate confidence so it means something.
CXWritten by the CXAstra teamProduct, research and customer teams

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