epok

Statistical

Post-Change Regression

Updated Jul 28, 2026 · 1d ago

Checks whether a deploy, config change or scale event actually made things worse, by comparing the window after the change against the matched window before it — per service.

Example alert

checkout: 3.8% error rate after deploy v2.3.1 vs 0.4% before (still elevated at window end)

Exact wording varies — the detector generates titles from the anomaly it finds. This is representative of what an alert looks like when it fires.

How it works

For each recent change event, compares a 30-minute before-window against a 30-minute after-window for the changed service, skipping a settling period so restart bursts and cold caches don't count as a regression. Absolute floors mean a rise from 0.01% to 0.1% stays silent despite being a 10x ratio, and the regression is re-checked at the end of the after-window so a burst that recovered is not reported. Learning period: 3 hours per service.

Availability

Runs on these tiers:

TrialTeamGrowthCustom

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