Frontend Engineer, AI Observability & Evals Platform

LangChain; Cambridge (MA); Hybrid; USD 160,000 - 195,000; Full time

Benefits offered by this job

Medical, dental, and vision

Flexible vacation

401(k)

Meals on in-office days

Job summary

LangChain is seeking a frontend engineer to build and enhance LangSmith features for observability, testing, and debugging of AI agents. The role supports an enterprise platform with a focus on robust UI in a fast-paced startup environment.

You will work in one of our offices (SF, NY, or Boston) or hybrid arrangements depending on location and role requirements. Strong React/TypeScript skills and a user-centric mindset are essential.

Qualifications

• 2+ years of Front-end engineering experience with React, JavaScript and TypeScript.
• Experience with modern front-end tooling and libraries.
• Familiarity with REST APIs and working with fullstack/backend engineers.
• Knowledge of JWT-based authorization and secure access patterns.
• Strong UX intuition and ability to translate designs into clean interfaces.

Responsibilities

• Develop new user-facing features using React and TypeScript.
• Build reusable components and front-end libraries.
• Translate designs into high-quality code and optimize performance.
• Collaborate with backend and UX/UI designers to improve usability.

Skills

React

TypeScript

JavaScript

REST APIs

JWT

UI/UX mindset

Communication

CS fundamentals

Education

BS in Computer Science

Tools

Babel

Vite

Webpack

NPM

Yarn

Job description

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:

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.

• This role can be based in our San Francisco, New York, or Boston office. Employees within commuting distance work from the office five days per week. Candidates who live outside commuting distance (e.g. >1hr each way), may be eligible for hybrid arrangements depending on location and role requirements.

What You Will Do:

• 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

What You Will Bring:

• 2+ years of Front-end engineering experience with strong proficiency in React, JavaScript and TypeScript
• 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

• Annual salary range: $160,000-$195,000 USD

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.