Grey box testing

Grey box testing is a method where the tester has partial knowledge of the application's internal structure. It is the middle ground between black box and white box testing. You might have access to the database schema or the API documentation while you test the user interface. This allows you to write better test cases because you understand the underlying logic.

It is particularly useful for integration testing where you want to see how data flows between different components. During refinement, you might use your knowledge of the system architecture to identify specific risks. By looking at the acceptance criteria and the technical design, you can ensure that the tests cover both the user journey and data integrity.

It helps to find bugs that a pure black box test would miss, such as a record not being updated correctly in the background or an API returning more data than it should. It is a smart way to test because it combines the user perspective with technical insight. You aren't just clicking buttons. You are verifying that the entire system is behaving as it should.