Frontend Engineer, AI Observability & Evals Platform

About the role

Frontend Engineer, AI Observability & Evals Platform

About LangChain

LangChain is dedicated to making intelligent agents a common reality in the world. The company constructs the foundational tools for agent engineering, enabling developers to transition AI agents from initial prototypes to robust, production-scale applications that entire teams can depend on. LangChain began as a set of widely adopted open-source libraries and has since expanded to provide a comprehensive platform for building, assessing, deploying, and managing agents at scale. The organization has secured $125 million in Series B funding from prominent investors including IVP, Sequoia, Benchmark, CapitalG, and Sapphire Ventures. This stage of growth is characterized by accelerating product development, rapid expansion, and the belief that every team member can significantly influence the company's direction and output. Professionals joining LangChain have the opportunity to directly shape how this technology is implemented in real-world applications.

The current platform consists of LangSmith, which provides observability, evaluation, deployment, fleet management, and sandboxes; open-source frameworks such as LangChain, LangGraph, and Deep Agents; and the recently introduced LangSmith Engine, designed for the autonomous improvement of agents. The company reports over 100 million monthly downloads of its open-source libraries, more than 6,000 active customers on LangSmith, and adoption by 5 of the Fortune 10 companies. also, 35% of the Fortune 500 utilizes LangSmith, with confirmed usage at organizations like Klarna, Clay, Coinbase, Workday, Lyft, Cloudflare, Harvey, Rippling, Vanta, LinkedIn, Monday.com, Nvidia, and Bridgewater.

The Role

The company is seeking a frontend engineer to join its efforts in developing and enhancing new features for LangSmith. This position focuses on the enterprise platform that delivers observability, evaluation, and debugging capabilities for LLM applications. The successful candidate will contribute to the product used for understanding agent behavior and refining evaluation workflows.

Location and Work Arrangements

This role offers three potential locations: San Francisco, New York, or Boston. Employees who work within commuting distance are expected to work from the office five days per week. Individuals residing further than a one-hour commute may be eligible for hybrid schedules, contingent on the specific location and the requirements of the role.

Responsibilities

The frontend engineer will be responsible for conceiving and implementing user-facing functionalities. The specific duties include:

• Architecting and developing modular React components tailored to enterprise evaluation requirements.
• Creating reusable frontend libraries and interface building blocks to support future product initiatives.
• Converting detailed design systems and wireframes into high-fidelity, interactive user interfaces.
• Optimizing application components to ensure peak performance across a wide range of devices and web browsers.
• Partnering with fullstack developers, backend engineers, and UX/UI designers to refine interaction design and usability.
• Directing agent evaluation workflows by leveraging the LangSmith Engine to ensure data accuracy and reliability.
• Constructing debugging panels that provide visibility into model behavior during active user sessions.
• Maintaining responsive and adaptive layouts that function effectively across the spectrum of modern devices.

Requirements

• Holding a minimum of two years of professional frontend development experience.
• Demonstrating expert-level proficiency in React, JavaScript, and TypeScript.
• Having hands-on experience with modern frontend toolchains, including Babel, Vite, Webpack, NPM, and Yarn.
• Understanding REST API architectures and experience collaborating with backend engineering teams.
• Knowledge of contemporary authorization protocols, such as JSON Web Tokens (JWTs).
• A strong passion for user experience, interface design, and the creation of clean, intuitive products.
• Excellent written and verbal communication skills, with the ability to convey technical information clearly to both technical and non-technical audiences.
• The adaptability to thrive in a fast-paced, startup-oriented environment and to identify high-impact tasks independently.
• A self-driven mindset with a proactive approach to finding opportunities and creating impact.
• A solid grasp of computer science fundamentals, with a preference for candidates with formal education in computer science or a related discipline.

Compensation and Benefits

The annual salary for this position ranges from $160,000 to $195,000 USD. This compensation package reflects LangChain's compensation philosophy, which includes base salary, potential variable compensation for applicable roles, meaningful equity, comprehensive benefits, and additional perks. Actual compensation and specific benefits may vary based on the role, professional level, and geographic location. Team members located in the European Union, the United Kingdom, and Asia Pacific regions receive benefits packages that are competitive within their local markets and comply with regional regulations.

Benefits provided by the company include medical, dental, and vision insurance, flexible vacation time, a 401(k) retirement plan, and meals on in-office days within the United States.