Senior Frontend Platform Engineer, Design Systems

LangChain is on a mission to make intelligent agents ubiquitous, providing a platform for building, evaluating, deploying, and operating AI agents at scale. The role involves building and evolving LangChain's component library to support frontend teams in delivering high-quality, accessible, and consistent UI components.

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
• 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
• 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.) 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