LangChain
Senior Fullstack Engineer, AI Observability & Evals Platform
$175K–$240K
Boston, MA +1 · On-site · Senior · Full-time · Posted Sep 12, 2026
- Location
- Boston, MA
New York, NY - Experience
- 5+ years.
About the job
Build and shape LangSmith’s observability and evaluation platform for AI systems, leading fullstack feature architecture and implementation.
What you'll do
- Lead technical architecture and implementation of key LangSmith features across the Go, Python, and Typescript stack.
- Collaborate with product and design teams to develop and iterate on features.
- Deliver projects on aggressive timelines while maintaining engineering standards and writing clean, maintainable, well-tested code.
What they ask for
- 5+ years of software engineering experience working on complex platform products.
- Fullstack 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.
Nice to have
- Experience with AI/LLM-powered applications, developer tools, or observability platforms.
Pay
$175,000-$240,000 USD (annual salary range; base salary)
Tools
Go, Python, Typescript, React, Postgres, Redis
AI focus
Build LangSmith’s platform for AI-system observability and evaluation; experience with AI/LLM-powered applications is a bonus.
Model-written summary · the original posting is authoritative