Senior Frontend Platform Engineer, Design Systems

🏢 About LangChain

At LangChain, our mission is to make intelligent agents ubiquitous. We build the foundation for agent engineering in the real world, helping developers move from prototypes to production-ready AI applications that teams can rely on.

With $125M raised at Series B from IVP, Sequoia, Benchmark, CapitalG, and Sapphire Ventures, LangChain powers over 100M monthly open-source downloads and serves 6,000+ active customers on LangSmith, including teams at Klarna, Cloudflare, Coinbase, Workday, Lyft, and 35% of the Fortune 500.

🎯 The Role

As LangChain's product surface grows, so does the need for a cohesive, scalable, and high-quality UI foundation. We’re looking for a Design Systems Engineer to build, own, and evolve LangChain’s shared component library — the foundation that our frontend teams rely on to ship quickly without sacrificing quality, accessibility, or consistency.

This role sits at the intersection of Design and Engineering. You will work closely with designers, product engineers, and platform teams to translate design intent into robust, reusable components.

This position can be based remotely in the U.S. (with hubs in San Francisco, New York, or Boston).

🛠️ Tech Stack

• Core: React, modern TypeScript, JavaScript, HTML5, Modern CSS
• Design Systems: Reusable Component Libraries, Design Tokens, Theming pipelines
• Styling: Tailwind CSS, CSS Modules, CSS-in-JS
• Tooling & Quality: Storybook, Chromatic, Visual Regression Testing, Package Bundling & Versioning

💼 What You'll Do

• Build out LangChain’s core component library, creating composable, flexible, accessible, and production-ready React primitives.
• Partner directly with designers to translate tokens, typography, and interaction patterns into code.
• Develop design system tooling around theming, token pipelines, versioning, and component discovery.
• Make architectural decisions that ensure high performance, accessibility (a11y), and visual consistency across all LangChain web products.
• Optimize build performance, bundling strategies, and package versioning for the component library.
• Maintain testing pipelines and dependency management across the UI stack.

✅ What You'll Need

• Extensive experience building modular, composable, and well-documented component libraries or design systems.
• Deep mastery of React, TypeScript, HTML, and modern CSS.
• Hands-on experience with design system tooling (Storybook, Chromatic, tokens pipelines, visual regression testing).
• Proven track record collaborating closely with product designers and front-end teams.
• Strong attention to visual craft, interaction fidelity, and digital accessibility (WCAG).

🌟 Nice to Have

• Experience building UI platforms in high-growth, developer-focused tooling or cloud infrastructure companies.
• Familiarity with AI developer workflows or building agent observability consoles.

🎁 Benefits

• Competitive base salary: $180,000 – $240,000 USD plus meaningful equity.
• Comprehensive medical, dental, and vision insurance.
• 401(k) retirement plan.
• Flexible paid vacation policy.
• Meals on in-office days in US hubs (SF, NYC, Boston).