Which testing method is aimed at deep integration of various subsystems in a larger system?

The integration test is specifically designed to facilitate the deep integration of various subsystems within a larger system. This stage of testing focuses on assessing the interactions and interfaces between different components after they have been individually tested through unit tests. By conducting integration tests, developers can identify issues that arise from the combination of these subsystems, ensuring that they work together as intended. This approach is crucial for verifying that data flows correctly between different parts of the application and that their functionality remains intact when integrated.

In contrast, unit tests focus on validating individual components in isolation, regression tests verify that new code changes do not adversely affect existing functionality, and system tests assess the complete and integrated software product to evaluate its compliance with specified requirements. Each testing method serves its own purpose within the software development lifecycle, but the integration test is particularly important for ensuring that all subsystems can function together harmoniously.