Senior QA / SDET Engineer

About LangChain

At LangChain, our mission is to make intelligent agents ubiquitous. We help developers build mission-critical AI applications across the entire agent development lifecycle. Our open source frameworks - LangChain and LangGraph - see over 70+ million downloads per month. Developers rely on LangChain for composable integrations and LangGraph for controllable agent orchestration. Our commercial agent platform, consisting of LangSmith and LangGraph Platform, enables teams to build, test, run, and manage agents at scale across their organization.

Founded in 2023, LangChain powers top engineering teams at companies like Replit, Lovable, Clay, Klarna, LinkedIn, and more.

About the role

In person 5 days / week in San Francisco, CA or New York, NY

We're hiring a Senior QA / SDET Engineer to own quality across our LangGraph Cloud / Platform and LangSmith products. You'll define the test strategy, build automation and tooling, and turn flaky, slow, or manual checks into fast, reliable, and observable pipelines. You'll work closely with Infra, Backend, and Frontend to ship with confidence across Kubernetes-based services, APIs, and UI flows-and you'll help pioneer quality practices specific to LLM applications (e.g., prompt regressions and evaluation suites).

• Own test strategy end-to-end across APIs, services, UI, data, and infra (K8s / Terraform / Helm).
• Build and maintain automation : API / integration tests (Python / pytest), E2E / browser tests (Playwright), load / soak tests (k6), contract tests, and smoke checks for production.
• Stand up ephemeral test environments in Kubernetes for PRs and release candidates; seed test data and run hermetic suites.
• Shift-left quality in CI / CD (GitHub Actions) : parallelization, caching, deterministic seeds, flake tracking, and quality gates.
• Observability for tests : rich failure artifacts (videos, logs, traces), Datadog dashboards, and actionable alerts.
• Performance & reliability : baseline SLIs / SLOs for critical paths; capacity tests and regression detection.
• Partner on incident workflows : reproduce issues, add focused regression tests, and improve runbooks / postmortems.
• Documentation : high-signal test plans, playbooks, and contributor guidelines for writing good tests.

Example projects you might own

How to be successful in this role

Bonus

Compensation & Benefits