Senior Fullstack Engineer, AI Observability & Evals Platform

LangChain • Cambridge, MA

20h • $175,000 - $240,000 • Onsite

About The Position

LangChain is seeking a Senior Fullstack Engineer to join the LangSmith team. This role will focus on building and enhancing LangSmith, LangChain's core platform for observability, evaluation, and production reliability of AI systems. The engineer will have the opportunity to shape the technical direction of the platform, working closely with enterprise customers, developer end-users, and internal stakeholders. The position is onsite 5 days/week in Boston, MA.

Requirements

• 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

Nice To Haves

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

Responsibilities

• 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.

Benefits

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

What This Job Offers

• Job Type: Full-time
• Career Level: Senior
• Education Level: No Education Listed