evidently-monitoring

Evidently is "an open-source Python library with over 40+ million downloads. It provides 100+ evaluation metrics, a declarative testing API, and a lightweight visual interface" per [Evidently docs].

When to use

• Pre-deployment gate: assert no data/target drift between candidate-model evaluation set and the production reference.
• Production monitoring: scheduled job comparing yesterday's traffic vs the reference window.
• Triage tool: when a model misbehaves in prod, run an Evidently Report comparing the bad period to a known-good window.

How to use