Design System
Overview
A design system is the single source of truth for an organization's UI — combining design tokens, component libraries, documentation, and tooling into a cohesive ecosystem. It ensures consistency, accelerates development, and bridges the gap between design and engineering.
Architecture Layers
┌─────────────────────────────────────────────────┐
│ Design (Figma) │
│ Variables, components, styles, auto-layout │
├─────────────────────────────────────────────────┤
│ Tokens (W3C DTCG / Style Dictionary) │
│ Color, typography, spacing, elevation, motion │
├─────────────────────────────────────────────────┤
│ Components (React, Vue, Angular, Web Comp.) │
│ Buttons, inputs, modals, cards, layouts │
├─────────────────────────────────────────────────┤
│ Documentation (Storybook) │
│ Stories, usage guidelines, interaction tests │
└─────────────────────────────────────────────────┘Design-to-Code Pipeline
Figma Variables ──► W3C DTCG JSON ──► Style Dictionary ──► CSS / SCSS / iOS / Android
│
Figma Components ──► Code Connect / Mitosis ──────────────► React / Vue / Angular / Svelte
│
▼
Storybook
(catalog + interaction tests)Token Architecture
Design tokens are the atomic values of a design system — colors, spacing, typography, elevation, motion. They flow through three tiers:
| Tier | Example | Purpose |
|---|---|---|
| Global | blue-500: #3b82f6 | Raw palette values |
| Alias / Semantic | color-primary: {blue-500} | Intent-based references |
| Component | button-bg: {color-primary} | Scoped to a specific component |
Component Strategy
Single-Framework
Build components in one framework (e.g., React) and use Storybook for documentation and testing.
Multi-Framework
Use an intermediary format to target multiple frameworks from a single source:
- Mitosis — JSX subset that compiles to React, Vue, Angular, Svelte, Solid, etc.
- Web Components — Framework-agnostic custom elements usable everywhere
- Stencil — Web Component compiler with lazy loading and SSR
Key Tools
| Tool | Role |
|---|---|
| Figma | Visual design, variables, prototyping, Dev Mode |
| W3C Design Tokens | Vendor-neutral token format (DTCG spec) |
| Style Dictionary | Transform tokens into platform-specific outputs |
| Storybook | Component catalog, docs, visual/interaction testing |
| Mitosis | Write-once component compiler for multiple frameworks |
| Tokens Studio | Figma plugin for managing tokens in DTCG format |
| Chromatic | Visual regression testing for Storybook stories |
File Structure
design-system/
tokens/
global/
colors.tokens.json # W3C DTCG format
typography.tokens.json
spacing.tokens.json
semantic/
theme-light.tokens.json
theme-dark.tokens.json
style-dictionary.config.mjs # Token build pipeline
src/
components/
Button/
Button.tsx # Component implementation
Button.stories.tsx # Storybook stories
Button.test.tsx # Unit / interaction tests
.storybook/
main.ts
preview.tsBest Practices
- Define tokens in W3C DTCG format for vendor neutrality — avoid locking into a single tool's proprietary format.
- Use three-tier token architecture (global → semantic → component) so themes only override the semantic layer.
- Use Style Dictionary to transform tokens into every platform your products target (CSS, SCSS, iOS, Android, Compose).
- Catalog every component in Storybook with args, docs, and play-function interaction tests.
- Use Figma Variables synced to your token files — Tokens Studio or Code Connect bridges the gap.
- For multi-framework orgs, evaluate Mitosis or Web Components before duplicating component code per framework.
- Automate visual regression testing with Chromatic or Percy in CI.
- Version your design system as a package — consumers should pin to semver releases.