What Is Test-Driven Development?A TechniqueDesigning and Structuring CodeA Bias Toward SimplicityIncreased ConfidenceWho Is This Book For?What Are the Prerequisites for Reading This Book?How to Read This BookFollow the Book One Language at a TimeFollow the Book in Two Languages First and Then in the Third LanguageFollow the Book in All Three Languages SimultaneouslyConventions Used in This BookTypographical ConventionsLexical ConventionsUsing Code ExamplesHow to Contact UsTDD—The WhysWhy Does This Book Use Go, JavaScript, and Python?Why Not This Other Language?Why Does This Book Have a “Chapter 0”?