Breaking change rate

What it means

Breaking change rate measures disruptive changes within a defined API or contract population. It can be calculated per release, per endpoint, or per interface change, but the classification must state what counts as breaking and how consumer impact is verified. The rate helps teams examine compatibility discipline.

Example

A service makes ten contract changes in a quarter, two of which remove fields without a compatibility window. The team adds deprecation checks and tests consumer expectations before the next release.

Limitations

A change can be technically compatible yet operationally disruptive through latency, ordering, or error semantics. Consumer inventories may be incomplete, so a low observed rate can undercount real impact.

How to use the signal

Pair the rate with consumer inventory and deprecation evidence, because an unobserved consumer can make a safe-looking release disruptive.

Weave can connect breaking changes to downstream rework, incident response, and review time. Keep compatibility analysis in API tooling and use Weave to trace the engineering outcomes.