Error-Budget Impact
Did this change consume an abnormal amount of reliability budget? A sensor that directly ties code changes to user-visible impact.
An error budget is the allowed amount of unreliability over a period (e.g., 99.9% uptime = 43 minutes of downtime per month). Error-budget impact measures whether a specific deployment consumed a disproportionate share of that budget — connecting code changes to user outcomes.
Sensor properties
| Property | Value |
|---|---|
| Oracle strength | Medium — budget burn is correlated, not causal |
| Independence | High — production measurements |
| Scope | System-level |
| Feedback latency | Hours |
| Actionability | Guiding — “this deployment burned 30% of the monthly budget” |
| Type | Retrospective |
What it cannot detect
Error-budget impact shows correlation between deployment and reliability degradation, but not causation. Other factors (traffic patterns, upstream failures) may contribute.