The change happened here. The regression appeared somewhere else.
A service change breaks a customer flow owned by another team.
The changed service still works the customer flow does not
The failure appears outside the component and team that made the change.
The changed service
The pricing rule still works.
Another team sees
Checkout now calculates the wrong total.
The failure crosses a boundary
The service returns a valid response. The frontend turns it into the wrong customer outcome.
One change reaches connected flows
Failure here source change there
The source is somewhere else
The visible failure and its source can belong to different components, repositories or teams.
Common patterns
Where regressions cross boundaries
01
Service dependencies
A contract changes and a dependent component interprets it differently.
02
Multi-step workflows
A local change alters a later step in the customer journey.
03
Team ownership
The regression appears in a system owned by another team.
04
Data contracts
A field keeps the same type but changes meaning for a connected component.
Run Early Regression Guard on your release candidate
Trace the impact. Decide what to fix.