React Design System for Scalable Applications
A production-grade design system built for a fintech platform, establishing shared component primitives, design tokens, and documentation for teams across 6 product surfaces.
Overview
A comprehensive design system delivered to a fintech company to unify the visual and interaction language across their web platform. The system covers primitive components, composite patterns, design token infrastructure, and interactive documentation — consumed by 4 engineering teams.
Context
The client had 4 product teams building independently with inconsistent UI patterns, duplicated component logic, and no shared design language. New features required disproportionate coordination overhead to maintain visual consistency.
Problem
Design and build a scalable component system that serves as the single source of truth for UI across all product surfaces, with strong token infrastructure, clear component APIs, and a documentation platform teams could contribute to.
Responsibilities
- ›Designed the full token architecture covering colors, spacing, typography, radius and shadows
- ›Built 60+ primitive and composite components with CVA variant APIs
- ›Established the Storybook documentation structure and contribution guidelines
- ›Implemented visual regression testing with Chromatic integrated into CI
- ›Facilitated design-engineering alignment sessions to anchor token decisions in Figma variables
Technical decisions
class-variance-authority for component variants
Used CVA to encode variant logic as typed configuration objects, making component APIs predictable, auto-completable, and decoupled from styling implementation details.
Radix UI for accessible primitives
Built interactive components on top of Radix UI headless primitives to guarantee ARIA compliance and keyboard navigation without handrolling complex accessibility behavior.
Design tokens as the single source of truth
Established a token layer in CSS custom properties that mirrors Figma variables, enabling design-to-code consistency and making global theme changes a single-file operation.
Architecture
Monorepo package structure with separate packages for tokens, primitives, and composites. Storybook as the primary documentation and visual testing surface. Chromatic as the CI visual regression gate.
Challenges
- ›Designing token naming conventions that remained meaningful across both design and engineering contexts
- ›Managing component API stability while iterating rapidly in early stages
- ›Achieving complete accessibility compliance across all interactive components
Results
Reduced UI-related PR review cycles by 52% across product teams
Achieved WCAG 2.1 AA compliance across all interactive components
Reduced time to implement new features by an average of 35% after adoption
Learnings
- ›Token naming is a communication contract — investing in the right taxonomy pays exponential returns in cross-functional alignment
- ›A design system is never finished; the sustainability model matters more than the initial scope