Principal Design Engineer

League; United States; Hybrid; USD 150,000 - 210,000; Full time

Benefits offered by this job

Medical, dental, vision coverage

Performance bonus

Employee stock options

Unlimited PTO

Wellness days

Mentorship program

Flexible remote days

Job summary

League seeks a senior contributor to own the end-to-end design system powering web, iOS, and Android surfaces. You will bridge design and engineering, shaping components, theming, tooling, and infrastructure so AI agents can build with the system reliably.

You will lead cross‑functional work, document workflows, and ensure accessibility is baked in. This role emphasizes leverage for others and standards over personal output.

Qualifications

• 6+ years in a hybrid design/frontend role, frontend engineering, product design, or design engineering.
• A portfolio of shipped work where the candidate did both the design and the build.
• Prior experience authoring a design system, with clear perspective on decisions, mistakes, and trade-offs.
• Strong design sensibility and the ability to articulate why a decision was right and what was traded away.
• Production-level fluency in React and TypeScript, including component API design, paired with deep Figma authoring skills.
• Daily, hands-on use of an AI coding agent such as Claude Code, including writing agent skills and benchmarking results.

Responsibilities

• Own and evolve the cross-platform design system, including component authoring and parity between the design library and shipped code.
• Maintain the tooling layer between design and code: token pipelines, plugins, and automated drift checks.
• Build the infrastructure that lets AI agents consume the design system correctly, including agent skills, reference documentation, and evals for output quality.
• Ship production code into the design system and the consuming surfaces, holding a single design decision that serves web, iOS, and Android.
• Set the accessibility baseline inside the system so product teams inherit it by default.
• Document AI workflows and raise the craft bar across the design practice through what ships.

Skills

Design system leadership

Cross-functional collaboration

Communication of trade-offs

Frontend design/engineering synergy

React proficiency

Tools

React

TypeScript

Figma

Claude Code

Job description

Role overview

A senior individual contributor role owning the end-to-end design system that powers every product surface across web, iOS, and Android. The position sits at the bridge between design and engineering, with responsibility for components, theming, tooling, and the infrastructure that lets AI agents build with the system correctly. Success is measured by the leverage the system gives other designers and engineers, not just personal output.

Responsibilities

• Own and evolve the cross-platform design system, including component authoring, theming architecture, and parity between the design library and shipped code.
• Maintain the tooling layer between design and code: token pipelines, plugins, and automated drift checks.
• Build the infrastructure that lets AI agents consume the design system correctly, including agent skills, reference documentation, and evals for output quality.
• Ship production code into the design system and the consuming surfaces, holding a single design decision that serves web, iOS, and Android.
• Set the accessibility baseline inside the system so product teams inherit it by default.
• Document AI workflows and raise the craft bar across the design practice through what ships.

Requirements

• 6+ years in a hybrid design and frontend role, frontend engineering, product design, or design engineering.
• A portfolio of shipped work where the candidate did both the design and the build.
• Prior experience authoring a design system, with clear perspective on personal decisions, mistakes, and trade-offs.
• Strong design sensibility and the ability to articulate why a decision was right and what was traded away.
• Production-level fluency in React and TypeScript, including component API design, paired with deep Figma authoring skills (variables, modes, component properties, design-to-code mapping).
• Daily, hands‑on use of an AI coding agent such as Claude Code, including writing agent skills, wiring MCP servers, and benchmarking results.

Nice to have

• Native iOS or Android experience.
• Tooling engineering in Node and TypeScript: CLIs, build scripts, token pipelines, CI automation.
• Server‑driven UI development.
• Background in health tech or another regulated industry.
• Experience designing evals or otherwise benchmarking AI output quality.

Benefits and work setup

• Comprehensive medical, dental, and vision coverage.
• Performance‑based bonus program and an employee stock option program.
• Unlimited paid time off, dedicated wellness days, and tax‑advantaged spending accounts.
• Mentorship program and explicit investment in growth and professional development.
• Flexible ways of working, with in‑office collaboration for nearby staff and a budget of flexible remote days per quarter for focus time.