Test-Driven Development
Test-Driven Development (TDD) is a software development methodology where developers write automated tests before writing the actual implementation code. It follows a strict cycle of 'Red-Green-Refactor': first write a failing test (Red), then write minimal code to pass the test (Green), and finally refactor the code for clarity and efficiency while keeping tests passing. This approach ensures code is thoroughly tested from the start and promotes clean, maintainable designs.
Developers should use TDD when building reliable, high-quality software, especially in agile environments where requirements evolve frequently. It's particularly valuable for complex systems, critical applications (e.g., finance or healthcare), and projects requiring high test coverage to reduce bugs and technical debt. TDD helps catch errors early, improves code design by encouraging modularity, and serves as living documentation for the codebase.