Senior Fullstack Engineer: AI Observability & Evaluations

LangChain, Inc.; Boston, Northern (MA, KY); Hybrid; USD 175,000 - 240,000; Full time

Benefits offered by this job

Medical, dental, and vision coverage

401(k) plan

In-office meals on days in US

Flexible vacation

Job summary

LangChain, Inc. in Boston, MA is seeking a Senior Fullstack Engineer to shape LangSmith's platform. You will own across Go, Python, and TypeScript, collaborating with enterprise customers and internal stakeholders to deliver scalable features.

This onsite role emphasizes hands-on leadership, clean code, and rapid iteration to meet ambitious timelines while maintaining high engineering standards.

Qualifications

• 5+ years of software engineering on complex platform products.
• Backend Go or Python, frontend React/Typescript experience.
• Strong knowledge of PostgreSQL and Redis.
• Experience designing and scaling high-performance APIs.
• Get stuff done attitude and shipping based on user feedback.

Responsibilities

• Lead the technical architecture and implementation across Go, Python, and TypeScript stack.
• Collaborate with product and design to iterate on features.
• Drive aggressive project timelines while maintaining engineering standards.
• Lead by example with clean, maintainable, well-tested code.

Skills

Fullstack engineering

Go or Python backend

React + Typescript frontend

PostgreSQL & Redis

API design & scaling

Strong communication

Ownership mindset

AI/LLM experience (bonus)

Job description

LangChain, Inc. in Boston, MA is seeking a Senior Fullstack Engineer to shape LangSmith's platform. You will own across Go, Python, and TypeScript, collaborating with enterprise customers and internal stakeholders to deliver scalable features.

This onsite role emphasizes hands-on leadership, clean code, and rapid iteration to meet ambitious timelines while maintaining high engineering standards.