Every codebase is a living system with its own conventions, boundaries, and architecture. Before you add to it, you need to understand it. Before you name something, you need to know why names matter. Before you draw a boundary, you need to see the shape of what’s already there.
This chapter covers the four foundational skills that separate engineers from people who just type code: reading existing code, naming things well, drawing boundaries, and seeing the shape of a system.
These aren’t glamorous skills. Nobody gets promoted for reading code. But every senior engineer I know spent years getting good at exactly this stuff.
Skip these and everything you build will be slightly wrong in ways you won’t notice until it’s too late. Learn these and you’ll write code that belongs — code that looks like it was always there.