What Is Feature Driven Development?

Use case-driven development, TDD (Test-Driven Development) Test-driven development is a core practice and technology in agile development and a design methodology. The principle of TDD is to write unit test case code before developing functional code. The test code determines what product code needs to be written. Although TDD is the core practice of agile methods, it is not only applicable to XP (Extreme Programming), but also applicable to other development methods and processes.