A design system is a collection of reusable components, patterns, and guidelines that help teams build consistent products efficiently. It's more than a style guide or component library. It's the single source of truth for how things should look and work.
What's in a Design System?
Design Tokens
The atomic values that define the visual language:
- Colors (primary, secondary, semantic)
- Typography (fonts, sizes, weights, line heights)
- Spacing (margins, padding, gaps)
- Shadows, borders, radii
Components
Reusable UI elements:
- Buttons, inputs, checkboxes
- Cards, modals, tooltips
- Navigation, headers, footers
- Data tables, forms, alerts
Patterns
How components combine to solve problems:
- Authentication flows
- Search and filtering
- Error handling
- Form validation
Documentation
Guidelines for usage:
- When to use each component
- Do's and don'ts
- Accessibility requirements
- Code examples
Benefits of Design Systems
Consistency
Users get a predictable experience. Every button looks and behaves the same.
Efficiency
Designers don't redesign the same component. Developers don't rebuild it. Everyone reuses.
Quality
Components are tested, accessible, and optimized once, then used everywhere.
Scalability
New pages and features can be built quickly from existing pieces.
Collaboration
Designers and developers share a common language.
Famous Design Systems
- Material Design (Google)
- Carbon (IBM)
- Polaris (Shopify)
- Atlassian Design System
- Lightning Design System (Salesforce)
Building a Design System
- Audit existing designs and identify patterns
- Define design tokens (colors, typography, spacing)
- Build core components
- Document usage guidelines
- Maintain and evolve over time
Design System vs. Component Library
A component library is the code implementation. A design system includes the library plus design files, documentation, guidelines, and principles.