Senior Frontend Platform Engineer, Design Systems

About Us 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 agents that teams can rely on. We began as widely adopted open-source tools and have grown to also offer a platform for building, evaluating, deploying, and operating agents at scale. With $125M raised at Series B from IVP, Sequoia, Benchmark, CapitalG, and Sapphire Ventures, we’re at a stage where we’re continuing to develop new products, growth is accelerating, and all team members have meaningful impact on what we build and how we work together. LangChain is a place where your contributions can shape how this technology shows up in the real world. Today, our platform includes LangSmith (Observability, Evaluation, Deployment, Fleet, and Sandboxes), our open source frameworks (LangChain, LangGraph, and Deep Agents), and the newly launched LangSmith Engine for autonomous agent improvement. We have 100M+ monthly open source downloads, 6,000+ active LangSmith customers, and 5 of the Fortune 10 use LangSmith in production (+ 35% of the Fortune 500 overall), including teams at Klarna, Clay, Coinbase, Workday, Lyft, Cloudflare, Harvey, Rippling, Vanta, LinkedIn, Monday.com, Nvidia, and Bridgewater. About the Role: This role can be based remotely in the U.S. Ideally SF, NYC, or Boston. LangChain is building the infrastructure that powers the next generation of AI applications. Our tools are used by thousands of developers and teams to build, debug, and ship production-grade LLM-powered products. As our product surface area grows, so does the need for a cohesive, scalable, and high-quality UI foundation . That’s where Design Systems comes in. We’re looking for a Design Systems Engineer to help build, own, and evolve LangChain’s component library —the foundation that our frontend teams rely on to ship fast without sacrificing quality, accessibility, or consistency. This role sits at the intersection of Design and Engineering . You’ll work closely with designers, product engineers, and platform teams to turn design intent into robust, reusable components and tooling that scale across the product. You’ll have ownership, influence, and your work will be directly consumed across LangChain’s products. What You'll Do: Build out LangChain’s component library Design and implement reusable, composable React components that are flexible, accessible, and production-ready Partner closely with designers to translate design systems, tokens, and interaction patterns into code Build reliable UI quality systems Develop design system tooling and improve workflows around theming, tokens, versioning, testing, and component discovery (e.g. Storybook) Make thoughtful architectural decisions that enable accessibility, performance, consistency, and maintainability across LangChain’s UI stack Improve UI build and test workflows Optimize build performance, bundling strategy, and package versioning for the component library Maintain tooling for testing, dependency management of the UI app What You'll Bring: Extensive experience building modular, composable, and well-documented component libraries and/or design systems Deep knowledge of React, TypeScript, HTML, and CSS, f amiliarity with: styling approaches (CSS Modules, CSS-in-JS, Tailwind, Sass, etc.) and design system toolings (Storybook, Chromatic, tokens pipelines, etc.) Experience collaborating closely with designers and non-engineering partners Strong attention to detail and a high bar for craft and genuine passion for accessibility and inclusive design Familiarity with testing UI components and visual regression testing Annual salary range: $180,000 - $240,000 Compensation Philosophy: We offer competitive compensation that includes base salary, variable compensation for relevant roles, meaningful equity, benefits, and perks. Actual compensation and offerings will vary based on role, level, and location. Team members in the EU, UK, and APAC receive locally competitive benefits aligned with regional norms and regulations. Benefits Benefits include medical, dental, and vision coverage, flexible vacation, a 401(k) plan, meals on in-office days in the US and more.