Explore the fundamentals of Test Driven Development (TDD) in this engaging 55-minute conference talk from NDC Oslo 2020. Discover the benefits of writing tests before coding, delve into architecture and design principles like SOLID, and learn how to create more testable and maintainable applications. Follow along with practical examples as the speaker demonstrates how to reprogram a T800 series Terminator, providing insights on implementing TDD in your own projects. Gain valuable knowledge on acceptance criteria, requirements, failing tests, refactoring patterns, and design patterns. Address common TDD failures and understand the cultural changes necessary for successful implementation. By the end of this talk, be equipped with the skills to write better code and potentially reprogram killer robots from the future.