Davide Bellone Yes, I have read your article about the diamond strategy, and I feel it doesn't quite fit with TDD. Test-driven development isn't just about testing; it's more about the development process as a whole. However, I do agree with your point about the importance of integration and end-to-end tests—these are crucial in the TDD approach as well. I find it challenging and expensive to cover numerous cases with integration or e2e tests. As you mentioned in your example, many cases were left untouched, even with a simple scenario. This issue becomes even more pronounced in complex enterprise-level applications, where the number of variables and potential cases for integration tests grows exponentially.