Senior Frontend Engineer, AI Observability & Evals Platform

LangChain; San Francisco (CA); On-site; USD 175,000 - 240,000; Full time

Benefits offered by this job

Medical, dental, and vision coverage

Flexible vacation

401(k) plan

Meals on in-office days in the US

Job summary

LangChain is seeking an experienced frontend engineer to develop and enhance features on LangSmith, our enterprise platform for LLM observability, testing, and debugging.

In this role, you will work on user-facing features, wireframes, and components, collaborating with cross-functional teams. The position is in-person 5 days/week in San Francisco, with additional sites in New York and Boston, and offers a competitive package.

Qualifications

• Extensive front-end engineering experience with React, JavaScript and TypeScript.
• Hands-on experience with front-end development tools like Babel, Vite, Webpack, NPM, and Yarn.
• Familiarity with REST APIs and collaboration with fullstack and backend engineers.
• Knowledge of modern authorization mechanisms, such as JWTs.
• A passion for user experience and building clean, intuitive interfaces.
• Strong written and oral communication skills for technical and non-technical stakeholders.
• Startup mindset and ownership—self-driven with opportunities to impact the company.

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 devices and browsers.
• Collaborate with fullstack/backend developers and UX/UI designers to enhance usability.

Skills

React

JavaScript

TypeScript

REST APIs

JWTs

UI/UX

Communication

CS fundamentals

Education

Bachelor's degree in Computer Science or related field

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.

About the role

(In person 5 days/week in San Francisco, CA, New York, Boston)

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. 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: $175,000-$240,000 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

• BenefitsBenefits include medical, dental, and vision coverage, flexible vacation, a 401(k) plan, meals on in-office days in the US and more.