TDD is a method of gradually incrementing software functionality toward a desired outcome. The incremental progress is driven by tests, followed by refactoring. TDD emphasizes minimal increments, which promise a self-emerging design. However, this approach can only lead to finding a local maximum—there is no guarantee of reaching the optimal solution. There is no evidence of any observable benefits from practicing TDD. Furthermore, software engineers should already write tests and perform refactoring as part of their daily practice, without needing a formal methodology to enforce these habits.