Regression testing should be triggered whenever code changes are introduced, including new features, bug fixes, dependency updates, or refactoring. As applications grow more complex, relying on ad-hoc validation increases the risk of unnoticed defects.
Regular regression testing helps teams confirm that existing functionality remains stable across builds and environments. Automated regression suites enable fast feedback, while selective manual testing supports validation of critical or high-risk areas.
By aligning regression testing with development milestones and CI workflows, teams can catch regressions early, reduce rework, and maintain consistent software quality throughout the delivery lifecycle.