Senior Backend Engineer (Growth Engineering)

About LangChain

LangChain was founded in early 2023 to help developers build context-aware reasoning applications. LangChain, open source software, is a framework that gives developers the building blocks to create production-ready applications with LLMs. LangSmith is our commercial, all-in-one SaaS platform that enables the end-to-end, development workflow for building LLM-powered apps. LangSmith is now trusted by the best teams building with LLMs, at companies such as Airbnb, ByteDance, Klarna, Google, Meta, Home Depot, and our 100+ paying enterprise customers.

Backed by some of the best venture capitalists, Benchmark and Sequoia, we have 10x’d our revenue last year and have big ambitions and are set up to build an enduring business.

About the role

In person 5 days/week in New York City, San Francisco or Boston

LangChain is seeking a Senior Backend Engineer to join our Growth Engineering team and drive development of features that power our product’s growth, monetization, and enterprise adoption. This is a rare 0→1 opportunity to join a just-formed, high-impact team where you will help shape the foundational architecture and technical direction and directly influence how LangChain is adopted across both startups and enterprises. The role involves close collaboration with cross-functional partners including GTM, Product Engineering, Analytics Engineering, and Infrastructure as well as some of our largest customers and design partners.

As a Senior Backend Engineer, you will own and evolve core platform systems related to authentication, authorization, billing, metering, and security while unlocking new ways for enterprise users to onboard, operate, and scale with LangChain.

Example challenges you might tackle:

• Implement attribute-based access control (ABAC) to extend our RBAC system with dynamic policy evaluation

• Enable secure and flexible OAuth token flows as an alternative to static API keys

• Create an extensible and scalable event delivery system for customer and internal integrations

• Develop a robust audit logging framework with fine-grained filtering, search, and export functionality to support enterprise compliance

• Allow seamless usage of various authentication modes across both cloud and self-hosted

Responsibilities:

• Lead the technical architecture and implementation of key enterprise-focused product features that directly impact growth and revenue.

• Innovate in how core systems (auth, billing, usage metering, auditability) are designed to support developer experience, flexibility, and robustness

• Mentor and guiding more junior members of the team.

• Drive aggressive project timelines while ensuring high engineering standards are being met.

• Lead by example in writing clean, maintainable, and well-tested code

• Stay up-to-date with emerging technologies and recommending options for the team to improve across dimensions like velocity and reliability.

How to be successful in this role

• 5+ years of experience in software engineering

• Strong knowledge in at least one of Go or Python

• Strong understanding of database systems, particularly Postgres and Redis.

• Experience designing and scaling APIs, preferably in a high-performance, data-intensive application.

• A “get stuff done” attitude—comfortable shipping fast and iterating based on user feedback.

• Excellent communicator who can navigate trade-offs and collaborate effectively with GTM, Product, and Infrastructure teams along with our design partners.

• Strong sense of ownership and accountability. Comfortable taking ambiguous goals and turning them into reliable systems.

• Bonus: Experience working on horizontal systems or features that support monetization or enterprise adoption

Compensation & Benefits

• Competitive salary and equity stake for role and stage of company. Commensurate with experience.

• Annual salary range: $165,000-$195,000 USD for Senior Engineers