FullStack Engineer, AI Observability & Evals Platform (LangSmith)

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. Today, our platform includes LangSmith, our open-source frameworks (LangChain, LangGraph, and Deep Agents), and the LangSmith Engine for autonomous agent improvement.

About the Role

We're looking for a Fullstack Engineer to work on LangSmith, our commercial AI observability and evals platform product. In this role, you'll have the opportunity to build new features and functionality for the platform while working closely with enterprise customers, developer end-users, and internal stakeholders.

What You Will Do

• Develop and implement key product features working across our entire Go, Python, and TypeScript stack
• Collaborate closely with product and design teams to iterate on new features and enhance the product roadmap
• Drive aggressive project timelines while ensuring high engineering standards are being met by writing clean, maintainable, and well-tested code

How to Be Successful in This Role

• 2+ years of experience in software engineering working on complex platform products
• Fullstack engineering experience with Go or Python on the backend and React + TypeScript on the frontend
• Solid understanding of database systems, particularly Postgres and Redis
• Experience designing and scaling APIs, preferably in high-performance, data-intensive applications
• Strong ownership and a “get stuff done” mindset - comfortable shipping fast and iterating based on user feedback
• Strong communicator with the ability to collaborate closely with various internal stakeholders and engage directly with our top-tier customers
• Bonus: Experience with AI/LLM-powered applications, developer tools, or observability platforms