The talk aims to highlight the importance of testing, why developers must spend more of their time testing, how testing generates more robust applications and why testing makes developers' lives easier. The talk is based around a live coding demo. The talk will: - Explain the difference between tests that prove an application works and tests which aim to break the application logic. - Highlight how test to break principles force developers to introduce logic to handle unexpected behaviour. - Show how test to break principles result in more robust applications as developers write code that can only be used in one way. - Encourage developers to apply test to break principles to all types of tests, including manual tests.