Security Engineer - Detection & Response

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.

The Security team ensures that while AI moves at breakneck speed, everyone driving the racecar is wearing a seatbelt. We secure LangChain's core platform and protect AI agents from emerging threats. We work across the stack so developers can confidently ship from prototype to production without compromising on safety or privacy.

You'll be the hands-on detection and response engineer responsible for how we see, stop, and learn from threats across LangChain's production platform, cloud infrastructure, and the services that host and execute agentic workloads. You'll partner closely with Product Security to turn threat models, vulnerabilities, and incidents into telemetry, detections, and durable defenses. Your primary focus is engineering: building detection, investigation, and response systems that scale the Security team's impact beyond what manual operations allow. We are looking for engineers who think like builders, not just operators — strong software skills are a must. This role participates in an incident on-call rotation, but its core focus is engineering systems that reduce risk, speed up investigations, and make incidents less frequent and less costly. Location/City: San Francisco or NYC What you'll do Own the detection lifecycle: Translate threat models, incidents, and attacker behavior into telemetry requirements and detections-as-code. Validate coverage, measure signal quality, tune false positives, and continuously test whether defenses work. Build security monitoring and telemetry: Design the telemetry pipeline end-to-end across cloud (GCP/AWS), Kubernetes, and the LangSmith/LangGraph control plane. Instrument services, define the signals that matter, and make security data reliable and useful. Engineer investigations and threat hunting: Build tools and workflows for proactive hunting, evidence collection, incident scoping, and containment. Turn investigation findings into new detections and lasting improvements. Use agents to scale the team: Build reliable internal AI agents and automation that triage alerts, enrich findings, gather evidence, scope incidents, and accelerate routine security work. Design human-in-the-loop controls and evaluations so automation is safe, observable, and trustworthy. Lead incident response and participate in on-call: Triage, scope, contain, and remediate security incidents, then drive postmortems that produce durable engineering changes. Partner with Product Security: Turn product threat models and vulnerability findings into production monitoring, and feed real-world detection and incident learnings back into secure design.

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