Senior Backend Engineer

About Us At LangChain, 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. LangChain is a place where your contributions can shape how this technology shows up in the real world. Today, our platform includes LangSmith (Observability, Evaluation, Deployment, Fleet, and Sandboxes), our open source frameworks (LangChain, LangGraph, and Deep Agents), and the newly launched LangSmith Engine for autonomous agent improvement. We have 100M+ monthly open source downloads, 6,000+ active LangSmith customers, and 5 of the Fortune 10 use LangSmith 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 Deployment team builds the platform that runs AI agents in production. We design and scale the core durable execution runtime to power reliable long-running agents with resumable streaming and inter-agent protocol support. We work closely with open source and other product teams to make it easy to bring any agent from prototype to production. About The Role We're building purpose-built infrastructure for running AI agents. Unlike traditional web apps, agents run for long durations, collaborate asynchronously with humans and other agents, and need to survive failures mid-execution. LangSmith Deployments is the runtime that makes this work, with durable checkpointing, fault-tolerant orchestration, and horizontal scaling, deployed across cloud and self-hosted environments. What You'll Do We're looking for a Senior Backend Engineer to work on this system. While the focus is on backend development, strong familiarity with Kubernetes (K8s), Terraform (Tf), and other DevOps tooling is highly preferred. Design distributed queue and worker systems that handle concurrent agent execution, background tasks, and multi-agent coordination across horizontally scalable infrastructureOwn core data infrastructure — state persistence, atomic job claiming, connection management, and schema evolutionCollaborate on architectural decisions, ensuring solutions are scalable and robust. Ship resumable streaming infrastructure so clients can disconnect and reconnect mid-execution without losing stateInstrument and monitor production systems — tracing, metrics, and alerting to keep the platform healthyParticipate in on-call rotations and own incident response for the runtimeCreate and maintain technical documentation, including system design and operational runbooks. Contribute to and extend open-source LangGraph, which is used by thousands of developers to build agent applications What You'll Bring 4+ years of professional backend engineering experienceStrong proficiency in Go and/or pythonExperience with distributed systems — conensus mechanisms, queueing, state machines, and/or workflow orchestrationExperience with scaling and sharding databases in high throughput environmentsFamiliarity with Kubernetes, infrastructure-as-code, and at least one major cloud platformStrong communication skills and ability to work cross-functionally on a small teamAnnual salary range: $175,000-$240,00 USD 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.