Senior Frontend Engineer, Observability & Evals Platform (LangSmith)

About LangChain

At LangChain, our mission is to make intelligent agents ubiquitous. We provide the agent engineering platform and open source frameworks developers need to ship reliable agents fast.

Our open source frameworks, LangChain and LangGraph, see over 90+ million downloads per month and help developers build agents with speed and granular control. LangSmith offers observability, evaluation, and deployment for rapid iteration, enabling teams to transform LLM systems into dependable production experiences.

LangChain is trusted by millions of developers worldwide and powers AI teams at companies like Replit, Clay, Cloudflare, Harvey, Rippling, Vanta, Workday, and more.

About the role:

In person 5 days/week in San Francisco, CA, New York, Boston, London, or Amsterdam

We’re looking to add a frontend engineer to develop and enhance new features on LangSmith, working on our enterprise platform product for LLM application observability, testing, and debugging. You will:

• Develop new user-facing features using React & Typescript

• Build reusable components and front-end libraries for future use

• Translate designs and wireframes into high-quality code

• Optimize components for maximum performance across a vast array of web-capable devices and browsers

• Collaborate with fullstack and backend developers and UX/UI designers, to enhance usability

In this role, you’re a good fit if you have:

• Front-end engineering experience with strong proficiency in React, JavaScript and Type

• Script

• Hands-on experience with front-end development tools like Babel, Vite, Webpack, NPM, and Yarn

• Familiarity with REST APIs and experience working closely with fullstack and backend engineers

• Knowledge of modern authorization mechanisms, such as JWTs

• A passion for user experience, design and building clean, engaging, and intuitive interfaces

• Strong written and oral communication skills, with the ability to explain technical concepts clearly and concisely to both technical and non-technical stakeholders

• The DNA to thrive in a start-up, fast-paced environment. Views unstructured environments as an opportunity to figure out the most impactful work and help define the future success of the company

• An ownership mind-set. You are self-driven and look for opportunities to make an impact.

• Strong computer science fundamentals, ideally with a degree in computer science or related field

Compensation & Benefits:

• We offer competitive compensation that includes base salary, meaningful equity, and benefits such as health and dental coverage, flexible vacation, a 401(k) plan, and life insurance. Actual compensation will vary based on role, level, and location. For team members in the EU and UK, we provide locally competitive benefits aligned with regional norms and regulations.

• Annual salary range: $155,000-$195,000 USD