JavaScript Engineer (Open Source Team)

About Us

At Lang Chain, our mission is to make intelligent agents ubiquitous. We build the foundation for agent engineering in the real world, helping developers move from prototypes to production-ready AI agents that teams can rely on. We began as widely adopted open-source tools and have grown to also offer a platform for building, evaluating, deploying, and operating agents at scale.

With $125M raised at Series B from IVP, Sequoia, Benchmark, CapitalG, and Sapphire Ventures, we’re at a stage where we’re continuing to develop new products, growth is accelerating, and all team members have meaningful impact on what we build and how we work together. Lang Chain is a place where your contributions can shape how this technology shows up in the real world.

Today, our platform includes Lang Smith (Observability, Evaluation, Deployment, Fleet, and Sandboxes), our open source frameworks (Lang Chain, Lang Graph, and Deep Agents), and the newly launched Lang Smith Engine for autonomous agent improvement. We have 100M+ monthly open source downloads, 6,000+ active Lang Smith customers, and 5 of the Fortune 10 use Lang Smith in production (+ 35% of the Fortune 500 overall), including teams at Klarna, Clay, Coinbase, Workday, Lyft, Cloudflare, Harvey, Rippling, Vanta, LinkedIn, Monday.com, Nvidia, and Bridgewater.

About the Team

The Open Source team builds and maintains the core libraries that developers use to build AI agents with Lang Chain. The team works directly with the open-source community to improve the ecosystem, maintain core packages, and ensure developers can reliably build and deploy production AI systems using Lang Chain.

About the Role

We’re looking to add a core maintainer to the Lang Chain team. This person would be responsible for maintaining and improving the LangChain JavaScript package. In-person in SF preferred.

What You'll Do

• Improve the core abstractions and runtime of the Lang Chain and Lang

Graph JavaScript packages:

• Improve documentation across the Lang Chain ecosystem

• Answer user questions and resolve issues from the developer community

• Use Lang Chain to build example applications that demonstrate best practices for developers building AI systems

What You'll Bring

• 3+ years of software engineering or applied machine learning experience

• A background in software engineering

• Strong written and oral communication skills, with the ability to explain technical concepts clearly and concisely to both technical and non-technical stakeholders

• The ability to thrive in a fast-moving environment and view unstructured environments as an opportunity to identify the most impactful work and help define the future success of the company

• An ownership-minded approach to work, with the ability to manage your work efficiently and effectively without the need for close supervision

Compensation

• Annual salary range: $160,000- $240,000

Compensation Philosophy:

We offer competitive compensation that includes base salary, variable compensation for relevant roles, meaningful equity, benefits, and perks. Actual compensation and offerings will vary based on role, level, and location. Team members in the EU, UK, and APAC receive locally competitive benefits aligned with regional norms and regulations.

Benefits

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