"Clean" Code, Horrible Performance (2023)

Many widely-taught "clean code" programming practices—such as using polymorphism over conditionals, keeping functions small, and following the DRY principle—can significantly harm runtime performance despite improving code readability and maintainability. Casey Muratori examines real-world performance costs of these guidelines by analyzing example code from clean code literature, demonstrating that following these rules objectively results in slower executing code. The article argues that while some clean code rules are arbitrary and don't affect performance, the structural rules that do impact runtime behavior often create unnecessary performance overhead.