Kevlin Henney It is all to easy to dismiss problematic codebases on some nebulous idea of bad practice or bad programmers. Poor code, however, is rarely arbitrary and random in its structure or formulation. Systems of code, well or poorly structured, emerge from systems of practice, whether effective or ineffective. To improve code quality, it makes more sense to pick apart the specific practices and see their interplay — the cause — than to simply focus on the code itself — the effect. This talk looks at how a handful of coding habits, design practices and assumptions can systematically balloon code and compound its accidental complexity.