Principal Design Engineer

We’re building the next generation of intelligent, human-centered products that improve people’s health and well-being. We’re looking for a Principal Design Engineer to own the bridge between design and code. Our design system serves web, iOS, and Android across every product and customer we support, which makes it the highest-leverage thing the design organization owns. You’ll own that system end to end: the component library, the theming architecture, the tooling that keeps design and code in sync, and the infrastructure that lets AI agents build with it correctly.

This is a senior individual contributor role. The work is infrastructure, so you’ll be measured by what other designers and engineers can build because of what you built.

• Own and evolve the design system: component authoring, theming architecture, and parity between the design library and what ships in code.
• Own the tooling between design and code, including token pipelines, plugins, and automated checks that catch drift before people do.
• Build the infrastructure that lets AI agents use our design system correctly, including agent skills, reference documentation, and evals that measure whether the output holds up.
• Ship production code into the design system and the surfaces that consume it.
• Hold the cross-platform constraint across web, iOS, and Android, so one design decision serves all 3.
• Set the accessibility bar inside the system so teams inherit it by default.
• Own the open architectural questions about the system and drive each one to a decision.
• Document and teach your AI workflows so the whole design practice improves, not only your own output.
• Set the craft bar through what you ship, and build alignment with designers, engineers, and leads who don’t report to you.

Benefits:

• Flexible medical and dental plans
• 401(k) and RRSP matching programs
• Health, lifestyle, learning and family spending accounts
• Employee stock option program (ESOP)
• Generous leaves (including parental and sabbatical)
• Flexible time off

A portfolio of shipped work where you did both the design and the build.

Qualifications:

• 6+ years in a hybrid design/frontend role, frontend engineering, product design or design engineering.
• You’ve authored a design system. We’ll ask which decisions were yours, what you got wrong, and what you’d do differently.
• Fluent in both halves of the job: production React and TypeScript with real judgment about component API design, and Figma at authoring depth (variables, modes, component properties, design-to-code mapping).
• You account for real-world complexity: edge cases, empty and error states, accessibility, and technical constraints.
• High agency. You pick up unowned work, form a position, and drive it to a decision.
• Daily, fluent use of Claude Code or equivalent, with hands-on experience writing agent skills, wiring up MCP servers, and benchmarking the results.
• Strong design sensibility. You care about craft, consistency, and interaction quality, and you can articulate why a decision was right and what you traded away to get there.
• Strong writing. Much of your output is documentation read by designers, engineers, and agents.
• Health tech or another regulated industry experience.
• Experience designing evals or otherwise benchmarking AI output quality.
• Server-driven UI development.
• Native iOS or Android experience.
• Tooling engineering in Node and TypeScript: CLIs, build scripts, token pipelines, CI automation.