SDK Engineer, Platform

About Lang Chain

At Lang Chain, our mission is to make intelligent agents ubiquitous. We provide the agent engineering platform and open source frameworks developers need to ship reliable agents fast.

Our open source frameworks, Lang Chain and Lang Graph, see over 90+ million downloads per month and help developers build agents with speed and granular control. Lang Smith offers observability, evaluation, and deployment for rapid iteration, enabling teams to transform LLM systems into dependable production experiences.

Lang Chain is trusted by millions of developers worldwide and powers AI teams at companies like Replit, Clay, Cloudflare, Harvey, Rippling, Vanta, Workday, and more.

About the role:

We are seeking a skilled software engineer to join our platform team, focusing on the development and maintenance of Lang Smith’s SDKs in various programming languages with a focus on Typescript, Python, Java and Go. This role is critical in enabling developers and businesses to seamlessly interact programmatically with Lang Smith and future products. The ideal candidate will have a strong background in software development, API and interface design, and cross-language SDK development.

What you will do:

• Design and build developer-friendly SDKs for the Lang Smith platform in Python and Type Script, with future expansion into Java and Go.

• Create clean, intuitive interfaces and abstractions that make it easy for developers to log traces, run evaluations, and integrate Lang Smith into their workflows.

• Develop and maintain integrations with popular SDKs and frameworks (e.g., OpenAI, Anthropic).

• Collaborate with the platform engineering team to ensure SDKs stay aligned with new features, API updates, and performance requirements.

• Partner with the documentation and product teams to produce high-quality docs, samples, and tutorials.

• Build robust testing and CI frameworks to ensure SDK reliability and performance across supported languages.

• Engage directly with developers and customers to gather feedback, troubleshoot issues, and improve usability.

• Stay current with evolving AI and developer ecosystems to identify opportunities for new integrations and platform enhancements.

About you:

• Proven experience designing and shipping SDKs and/or developer libraries used by external developers.

• Deep programming expertise in Python and Type Script, with familiarity in one or more additional languages (Go, Java, etc.).

• Strong understanding of API design, developer ergonomics, and client library best practices.

• Excellent problem-solving skills and ability to work autonomously in a fast-paced environment.

• Strong communication skills, able to collaborate effectively and explain technical concepts clearly.

• Experience with Git-based workflows, CI/CD pipelines, and automated testing.

• Comfort working in an early-stage environment with evolving priorities and high ownership expectations.

Compensation:

We offer competitive compensation that includes base salary, meaningful equity, and benefits such as health and dental coverage, flexible vacation, a 401(k) plan, and life insurance. Actual compensation will vary based on role, level, and location. For team members in the EU and UK, we provide locally competitive benefits aligned with regional norms and regulations. Salary Range: $170,000 - $195,000

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