Design Systems, Components, and Dev Handoff

Ask a candidate "what's a design system?" and the most common answer is "a Figma file with a bunch of reusable components." It's not wrong, exactly — it's just describing the artifact, not the thing that makes it valuable. A component library sitting in a Figma file with no documentation, no versioning, and no agreement about who can edit a shared component isn't a design system, it's a shared sketchbook that will drift out of sync with the real product within a quarter. What interviewers are actually listening for is whether you understand a design system as infrastructure — governed, documented, and treated with the same rigor as a shared code library — because that's the difference between a design system that scales past one team and one that quietly becomes five slightly different buttons.

This subject covers what a design system actually is, the atomic design vocabulary used to talk about component hierarchy, design tokens as the mechanism that makes theming and rebrands cheap, the governance practices that keep a shared library from drifting, and how dev handoff changes once components and tokens are shared infrastructure rather than a static spec. It closes with the most interview-savvy point in the whole topic: knowing when not to build a formal design system is as much a signal of seniority as knowing how to build one.

This is also one of the few topics in a UI/UX interview where the interviewer is often an engineer, or a mixed panel, rather than only designers — "walk me through how your design system works" is as much a question about process and collaboration discipline as it is about visual taste, which is why the strongest answers here lean on concrete mechanics (tokens, versioning, a named contribution rule) rather than describing "consistency" as a vague aspiration.