> For the complete documentation index, see [llms.txt](https://docs.layerlens.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.layerlens.ai/more-in-this-section-4/investigate-ci-regression.md).

# Investigate a CI regression

Guide — investigate a regression flagged by CI.

1. Open the failing eval run in Premium
2. Compare to the prior baseline run — Stratix highlights newly-failing rows
3. Open one or two failing rows; read the input/output/expected
4. Hypothesize: prompt change? Model change? Data drift?
5. Test the hypothesis by reverting one variable and re-running

## See also

* [Tutorial 3: CI/CD gates](/6.-build-wire-your-code/03-cicd-gates.md)
* [Workflow: Improve](/6.-build-wire-your-code/workflow.md)