Which type of testing should a Technical Architect implement to reduce complaints from users about recent changes breaking existing functionality?

Regression Testing is essential for verifying that recent changes to a system have not adversely affected existing functionality. When modifications are made, whether through new features, bug fixes, or system upgrades, there is always a risk that these changes might inadvertently impact the software's previous behavior.

The primary goal of regression testing is to ensure that the previously developed and tested software still performs as expected after changes are implemented. This type of testing allows the Technical Architect to identify any issues that may arise from recent changes, thereby minimizing user complaints about broken functionality. By executing regression tests, the team can catch any unintended side effects caused by code alterations before the software updates are released to end-users.

While performance testing focuses on assessing how the system behaves under load and user acceptance testing gauges whether the system satisfies the needs of the end-users, neither specifically addresses the need to confirm that existing features remain intact after changes. Unit testing, on the other hand, deals with individual components of the software, ensuring that they work correctly in isolation, but it does not cover the interactions between different system parts that may be affected by recent updates.