LangChain
Senior Frontend Engineer, AI Observabilty Platform
$170K–$235K
Boston, MA · On-site · Senior · Full-time · Posted Sep 24, 2026
- Experience
- Extensive frontend engineering experience; no number of years stated.
- Education
- Ideally a degree in computer science or a related field.
About the job
Develops user-facing features for LangSmith, an enterprise platform for LLM application observability, testing, and debugging.
What you'll do
- Build React and TypeScript features, reusable components, and frontend libraries.
- Translate designs and wireframes into high-quality code and optimize performance across devices and browsers.
- Collaborate with fullstack and backend developers and UX/UI designers to improve usability.
What they ask for
- Extensive frontend engineering experience with strong proficiency in React, JavaScript, and TypeScript.
- Hands-on experience with frontend development tools such as Babel, Vite, Webpack, NPM, and Yarn.
- Familiarity with REST APIs and knowledge of modern authorization mechanisms such as JWTs.
- Strong computer science fundamentals; degree in computer science or a related field is described as ideal.
Pay
$170,000-$235,000 USD (base salary)
Tools
React, Typescript, JavaScript, Babel, Vite, Webpack, NPM, Yarn
AI focus
Builds frontend features for an LLM application observability, testing, and debugging platform.
Model-written summary · the original posting is authoritative