Senior Frontend Platform Engineer, Design Systems

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 offer a platform for building, evaluating, deploying, and operating agents at scale. 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. With $125M raised at Series B from IVP, Sequoia, Benchmark, CapitalG, and Sapphire Ventures, 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.

About the Role

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. 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.

Responsibilities

• Build and own 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

Requirements

• Strong experience building modular, composable, and well-documented component libraries and/or design systems
• Deep knowledge of React, TypeScript, HTML, and CSS
• Familiarity with:
  • Styling approaches (CSS Modules, CSS-in-JS, Tailwind, Sass, etc.)
  • 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
• Genuine passion for accessibility and inclusive design
• Familiarity with testing UI components and visual regression testing

Pay

Annual salary range: $170,000 - $195,000

Benefits

• Medical, dental, and vision coverage
• Flexible vacation
• 401(k) plan
• Life insurance
• Meals on in-office days in the US

Team members in the EU, UK, and APAC receive locally competitive benefits aligned with regional norms and regulations.