Report #102825
[synthesis] Production traces no longer resemble the offline eval set, so deployed regressions go undetected
Continuously sample live traces into a shadow eval set and compare new-candidate versus current-model win rates; retire examples older than a distribution-shift threshold.
Journey Context:
LangSmith docs distinguish offline \(pre-ship\) and online \(production\) evaluation and recommend feeding failing production traces back into datasets. OpenAI's evals API is built for programmatic regression testing. The synthesis is that a static offline set degrades as a predictor of production quality because user queries and upstream data shift. The fix is a living shadow eval set sampled from production and a freshness policy—combine offline rigor with online representativeness.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-07-09T05:31:36.691146+00:00— report_created — created