Sr. Design System Engineer

About the Team

The Design Foundations team is a small group of designers and engineers focused on improving the quality and efficiency of product design. We build the tools, practices, and processes used by all designers and front‑end engineers across the organization. Our most established work includes two design systems:
Interstate (for B2B products) and Iris (for consumer‑facing products). More recently, we've been building AI tools like context packs, MCP tools, and Claude skills that deliver on our mission of quality and efficiency.

We're looking for a Senior Software Engineer to help build, evolve, and scale our design system: the shared foundation beneath every product UI we ship. You'll work at the intersection of design and engineering, building React and web components, managing design tokens, creating AI‑powered tooling, and ensuring our system raises the quality bar across everything we build.

This isn't a role where you maintain a component library in isolation. You'll work closely with product designers, product engineers, and the broader organization to create tools, components, and infrastructure that make everyone around you faster and better. As AI‑assisted development accelerates, the design system becomes the source of truth that ensures quality and consistency at scale, whether a component was composed by a person or an agent.

This role sits at the center of that shift.

• Build, maintain, and evolve a cross‑platform design system spanning React components and web components, with thoughtful, composable APIs that prioritize developer ergonomics.
• Manage our design token architecture, from primitive values to semantic and component‑level tokens, bridging Figma and code to ensure visual consistency across platforms.
• Build and utilize MCP tools, skills, AI agents, and internal tooling that leverage the design system to accelerate product development. Make the system machine‑readable so AI can compose UIs using our components correctly.
• Create and maintain documentation, interactive playgrounds, and component showcases that make adoption effortless. Mentor engineers across the organization on design system best practices.
• Champion accessibility and infrastructure: automated a11y testing, WCAG compliance, CI/CD pipelines, visual regression testing, versioning, and release management.
• Collaborate deeply with product designers to bridge design intent and engineering implementation, contributing to the design process from ideation through production.

We care about the depth and quality of your experience more than years on a resume. That said, candidates who thrive in this role typically have 5+ years of frontend engineering experience. Direct design systems experience is a plus, not a prerequisite.

• Deep in Type Script and React, including advanced patterns like compound components, headless UI, and controlled/uncontrolled APIs. Experience with (or strong interest in) web components and custom elements.
• Bachelor's degree in Computer Science or related discipline, and 4 years' experience in a related field. The right candidate could also have a different combination, such as a master's degree and 2 years' experience; a Ph.D. and up to 1 year of experience; or 16 years' experience in a related field.
• A systems thinker. You've used component libraries, understood their constraints, and have opinions about what makes them good or bad. You naturally see patterns, design for reuse, and anticipate how your decisions cascade across a product.
• Familiar with design token tooling and workflows:
  Style Dictionary, Figma variables/tokens, token transforms, and the full pipeline from design to code.
• Accessible by default. Strong understanding of WCAG and hands‑on experience testing for accessibility across browsers and assistive technologies.
• Fluent in AI‑assisted development. You already use AI tools in your day‑to‑day work, whether that's MCP servers, LLM tooling, prompt engineering, or agent‑based workflows. The playbook for 'design systems + AI' is being written right now, and you want to help write it.
• Visually literate. You don't need to be a designer, but you understand…