Product teams that skip the style guide pay for it later — across multiple sprints. Buttons appear in three shades of the brand color depending on which designer touched that screen. Heading sizes drift across modules. Spacing tokens get hardcoded differently by different developers. By the time the inconsistency is visible to users, it's woven into the codebase.

A UI design style guide prevents this — but only if it's built with a tool that can actually scale with the product. Most teams start with a Figma page of color swatches and call it done. That approach lasts until the product grows past three or four screens.…