Senior Full Stack Engineer, Observability & Evals Platform (LangSmith)

About LangChain

At LangChain, our mission is to make intelligent agents ubiquitous. We provide the agent engineering platform and open source frameworks developers need to ship reliable agents fast.

Our open source frameworks, LangChain and LangGraph, see over 90+ million downloads per month and help developers build agents with speed and granular control. LangSmith offers observability, evaluation, and deployment for rapid iteration, enabling teams to transform LLM systems into dependable production experiences.

LangChain is trusted by millions of developers worldwide and powers AI teams at companies like Replit, Clay, Cloudflare, Harvey, Rippling, Vanta, Workday, and more.

About the role:

In person 5 days/week in San Francisco

We're looking for a Senior Full Stack Engineer for our commercial product LangSmith, an observability and evals platform. In this role, you'll have the opportunity to shape the technical direction of our platform while working closely with enterprise customers, developer end-users and internal stakeholders.

• Lead the technical architecture and implementation of key product features for LangSmith, working across our entire Go, Python, and Typescript stack.

• Collaborate closely with product and design teams to iterate on new features.

• Mentor and guide more junior members of the team. Drive aggressive project timelines while ensuring high engineering standards are being met.

• Lead by example in writing clean, maintainable, and well-tested code

How to be successful in this role

• 7+ 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.

• Strong understanding of database systems, particularly Postgres and Redis

• Experience designing and scaling APIs, preferably in a high-performance, data-intensive application

• A “get stuff done” attitude - 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

• Strong ownership mindset

• Bonus: Experience with AI/LLM-powered applications, developer tools, or observability platforms

Compensation & Benefits

• We offer competitive compensation that includes base salary, meaningful equity, and benefits such as health and dental coverage, flexible vacation, a 401(k) plan, and life insurance. Actual compensation will vary based on role, level, and location. For team members in the EU and UK, we provide locally competitive benefits aligned with regional norms and regulations.

• Annual salary range: $165,000-$198,000 USD