Explore the critical importance of unit testing and test-driven development (TDD) in software engineering through this insightful 47-minute conference talk from GOTO Copenhagen 2022. Discover how abandoning tests can negatively impact your codebase and learn practical strategies to improve code quality. Delve into topics such as encapsulation, single responsibility principle, debugging, fast feedback, edge cases, and productionizing spikes. Gain valuable insights on how TDD enhances code maintainability, facilitates refactoring, and accelerates development processes. Follow along with real-world examples and expert advice to understand why unit tests, TDD approaches, and pair programming are essential for creating robust, efficient software.