Drift & decay monitoring
Re-run a fixed suite against each release and over time, watching for the quiet regressions and capability decay that a one-off evaluation can't see.
Published August 22, 2026
How it works
Models don't only improve — fixes come undone, behaviours shift under silent updates, and accuracy on a task you relied on can decay between releases. Drift monitoring keeps a stable, versioned suite and re-runs it continuously, comparing each result against the baseline so a regression shows up as a trend, not a surprise in production. It is the longitudinal complement to benchmarking: benchmarks tell you where you stand, drift monitoring tells you which way you're moving.
When to use it
Long-lived systems on top of a model you don't control; tracking hosted models that update silently; guarding against regressions resurfacing after a fix; and as a standing safeguard for any system whose vendor doesn't publish a changelog for model updates, where drift monitoring is the only signal a behavior actually changed underneath you.
Limitations
Only as sensitive as the suite it re-runs — a drift in a capability the suite never exercised is invisible — and a drift signal flags that something moved without explaining why. Needs a stable baseline and disciplined versioning to avoid false alarms, and the suite itself has to be maintained as the product changes or it starts measuring the wrong thing.
Cite this
Qlarify Labs. (2026). Drift & decay monitoring. Retrieved from https://labs.qlarify.fi/evals/drift-monitoring


