Senior Fullstack Engineer (AI)

Location: On-site 5 days per week in Boston, MA, United States

Annual salary: $175,000–$240,000 USD

Company

LangChain builds open-source frameworks and a platform for developing, evaluating, deploying, and operating AI agents at scale.

What you will do

• Lead the architecture and implementation of key LangSmith platform features.
• Develop across the Go, Python, TypeScript, and React stack.
• Collaborate with product and design teams to iterate on new functionality.
• Drive fast project delivery while maintaining high engineering standards.
• Write clean, maintainable, well-tested code and engage directly with enterprise customers and developer users.

Requirements

• 5+ years of software engineering experience working on complex platform products.
• Fullstack engineering experience with Go or Python on the backend and React with TypeScript on the frontend.
• Strong understanding of database systems, particularly Postgres and Redis.
• Experience designing and scaling APIs for high-performance, data-intensive applications.
• Strong communication, ownership, and ability to collaborate with internal stakeholders and customers.

Nice to have

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

Culture & Benefits

• Meaningful impact on product direction and technical decisions.
• Medical, dental, and vision coverage.
• Flexible vacation and a 401(k) plan.
• Meals provided on in-office days in the United States.
• Base salary, variable compensation where relevant, equity, and additional perks.