Design System per Applicazioni Web

Design System per Applicazioni Web

Un design system è una raccolta di componenti riutilizzabili, guidati da standard chiari, che possono essere assemblati per costruire qualsiasi numero di applicazioni. Colma il divario tra design e engineering.

Elementi Fondamentali

Design Tokens: Colori, spaziatura, tipografia, ombre, raggi, motion, z-index (platform-agnostic, JSON/YAML). Componenti: Button, input, modal, table, navigation, feedback (React, Vue, Web Components). Pattern: Layout, form, data display, navigation flow. Guideline: Uso, accessibilità, contenuto, branding. Documentazione: Interattiva (Storybook), ricercabile, versionata.

Design Tokens

Single source of truth per decisioni design. Formato: JSON (Style Dictionary, Theo), Figma variables. Struttura: Global (color.blue.500), Semantic (color.primary), Component (button.background). Transform: CSS custom properties, SCSS variables, JS/TS objects, iOS/Android XML. Theming: Light/dark, brand, high-contrast via token swap.

Architettura Component Library

Monorepo: Nx, Turborepo, pnpm workspaces. Framework: React (più comune), Vue, Svelte, Web Components (framework-agnostico). Styling: CSS-in-JS (Stitches, Panda), Tailwind, CSS Modules, Vanilla Extract. State: Uncontrolled (native), Controlled (React), Compound components. Composition: Slots, render props, asChild (Radix/Polymorphic).

Documentazione con Storybook

Storybook: Component explorer, docs, testing. Stories: Canvas (interattivo), Docs (MDX), Controls (props), Actions (eventi), Backgrounds, Viewport. Addons: Accessibility (a11y), Viewport, Measure, Outline. Chromatic: Visual testing, review, publishing. Auto-docs: Genera da component props (TypeScript).

Versioning e Release

Semantic versioning: Major (breaking), Minor (nuove feature), Patch (fix). Changesets: Changelog automatizzati, version bump. Peer dependencies: React, React-DOM come peers. Deprecation policy: Warn, migrate, remove. Migration guides: Codemods per breaking changes. Distribuzione: npm (pubblico/privato), GitHub Packages, JSR.

Strategie Adozione

Greenfield: Inizia con design system. Brownfield: Adozione incrementale (wrapper componenti, alias import). Design system team: Platform team model (abilita, non gatekeep). Contribuzione: Processo RFC, design review, mentalità open source. Metriche: Tasso adozione, uso componenti, impatto bundle size, developer satisfaction.

Handoff Design-Engineering

Figma: Componenti, varianti, auto-layout, variables (token). DevMode: Inspect, copia codice, asset. Sync: Figma → Code (token, componenti), Code → Figma (Storybook embed). Anima, Builder.io, Locofy: Design-to-code (usa con cautela). Single source of truth: Token in codice, sincronizzati a Figma.

Testing e Qualità

Unit: Vitest + Testing Library (comportamento). Visual: Chromatic (snapshot), Percy. Accessibilità: axe-playwright, Storybook a11y addon. Interazione: Playwright component testing. Bundle size: bundlesize, size-limit. Performance: Lighthouse CI su Storybook. Cross-browser: BrowserStack, Sauce Labs.

Design System Popolari

Open Source: Radix UI (headless), shadcn/ui (copy-paste), Chakra UI, MUI (Material), Ant Design, PrimeVue, DaisyUI (Tailwind), Flowbite. Enterprise: Adobe Spectrum, IBM Carbon, Google Material, Microsoft Fluent, Salesforce Lightning, Atlassian Design System. Headless + Styling: Radix + Tailwind, Ark UI + Panda CSS.