Senior Frontend Engineer, Design System

Role overview

Senior Software Engineer on the Design System team at Synthesia. You will be a co-owner of the shared UI foundation used across all Synthesia products, shaping direction and making key decisions with the team. The core challenge is making the foundation AI-friendly so both humans and AI agents can build on-brand, accessible, correct-by-construction interfaces.

Responsibilities

• Build, scale, and evolve the design system: component library, design tokens, and documentation for consistent, accessible product development.
• Extend the design system for AI-assisted development, so AI coding tools/agents can consume components, tokens, and guidelines easily.
  • Use Storybook as the backbone and add machine-readable interfaces (e.g., MCP).
• Design component APIs that resist misuse for both AI and human developers.
• Write high-quality, performant frontend code using React/TypeScript, raising the bar for component craft and consistency.
• Partner with design, product, and engineering to define components and ensure they are production-ready.
• Ensure components are accessible by default, meeting WCAG 2.2 AA (and aligning with EN 301 549), working closely with an Accessibility engineer.
• Own developer experience for the design system: documentation, guidelines, Storybook, component API design, versioning, and migration paths.
• Implement and maintain theming, white labeling, and localization/RTL support.
• Continuously improve the system using adoption metrics, contributor feedback, and new platform capabilities.
• Shape technical direction for the next 6–12 months and champion adoption across teams.

Requirements

• 5+ years software engineering experience, including 3+ years at senior level.
• Proven ownership of a design system/shared component library used across multiple products.
• Expert HTML, CSS, and JavaScript/TypeScript; strong React and familiarity with modern build tooling.
• Strong knowledge of component API design, versioning, and developer experience for shared libraries.
• Experience or strong interest in making component libraries consumable by AI.
• Strong understanding of responsive design, cross-browser compatibility, and web performance.
• Comfortable building to WCAG 2.2 AA / EN 301 549 and validating with keyboard and screen reader.
• High attention to detail and strong craft; ability to balance design considerations (sentence truncated in source).