Senior Frontend Engineer, AI Observability & Evals Platform

LangChain; United States; Remote; USD 180,000 - 240,000; Full time

Benefits offered by this job

Medical, dental, vision

401(k) plan

Flexible vacation

Meals on in-office days

Job summary

LangChain is seeking an experienced frontend engineer to build and enhance features for LangSmith, our enterprise platform for LLM observability, testing, and debugging. The role supports a remote-first environment with US-based applicants and a strong emphasis on user-centered design.

You will collaborate with backend teams, UX/UI designers, and other engineers to deliver scalable, high-performance interfaces across browsers and devices.

Qualifications

• Extensive 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.

Responsibilities

• 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.

Skills

React

JavaScript

TypeScript

UX/UI

Communication

CS fundamentals

JWTs

Education

Bachelor's 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:

This position can be based remotely in

We’re looking to bring on an experienced frontend engineer to develop and enhance new features on LangSmith, our enterprise platform product for LLM application observability, testing, and debugging.

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

• Extensive 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. You view unstructured environments as an opportunity to make the most impactful work and to help define what’s next.

• 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: $180,000-$240,000 USD

Compensation Philosophy:

We offer competitive compensation that includes base salary, variable compensation for relevant roles, meaningful equity, benefits, and perks.

We are hiring for this role across a range of scope, and the compensation band reflects that. Your offer depends on what we learn about your impact, craft, leadership, and communication during the interview process. We will tell you early where you’re tracking and talk comp with you before offer stage. 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.

This is a remote role. Applicants must be located in: United States.