Senior Fullstack Engineer, AI Observability & Evals Platform

About the Role

This role is onsite 5 days/week in Boston, MA.

We're looking for a Senior Fullstack Engineer to work on LangSmith. In this role, you'll have the opportunity to shape the technical direction of our platform while working closely with our enterprise customers, developer end-users, and cross functional internal stakeholders.

What You Will Do

• 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.
• Help drive aggressive project timelines while ensuring high engineering standards are being met.
• Lead by example in writing clean, maintainable, and well-tested code.

What You Bring

• 5+ 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