> 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-7/curate-regression-set.md).

# Curate a regression test set

Guide — curate a regression test set from production traces.

1. Tag interesting traces in production (`good`, `bad`, `edge-case`).
2. Group tagged traces into a **trace set**.
3. Use the trace set as the input to a regression evaluation.
4. Review and re-tag periodically; retire stale items.

## See also

* [Concept: Traces and spans](/6.-build-wire-your-code/traces-and-spans.md)
* [Workflow: Observe](/9.-improve-tune-the-system/workflow.md)