Build Engineer - Bazel - #4770

Our mission is to detect cancer early, when it can be cured. We are working to change the trajectory of cancer mortality and bring stakeholders together to adopt innovative, safe, and effective technologies that can transform cancer care.

We are a healthcare company, pioneering new technologies to advance early cancer detection. We have built a multi-disciplinary organization of scientists, engineers, and physicians and we are using the power of next-generation sequencing (NGS), population-scale clinical studies, and state-of-the-art computer science and data science to overcome one of medicine’s greatest challenges.

GRAIL is headquartered in the bay area of California, with locations in Washington, D.C., North Carolina, and the United Kingdom. It is supported by leading global investors and pharmaceutical, technology, and healthcare companies.

For more information, please visit

GRAIL is seeking a Build Engineer to join our Dev Ops / Platform Engineering organization. Our team builds and operates the infrastructure, tooling, and developer platforms that engineering and research teams rely on to move quickly and safely, from local development environments through builds, tests, CI/CD, and release.

In this role, you will focus on developer experience: reducing friction in day-to-day engineering workflows and making complex, multi-language systems easier to build, test, and maintain. You will own and improve build-system workflows in our Bazel-based monorepo, raise CI reliability and performance, and build internal tooling and self-service automation used across engineering and research. This is a high-leverage role with broad visibility, your work directly accelerates teams working on early cancer detection.

This role is based in Sunnyvale, California. We are moving to our new headquarters in September so you may visit our current Menlo Park, CA location for interviews if they occur prior to the move. This role offers a flexible work arrangement, with the ability to work from GRAIL's office or from home. Our current flexible work arrangement policy requires that a minimum of 60%, or 24 hours, of your total work week be on-site.

Your specific schedule, determined in collaboration with your manager, will align with team and business needs and could exceed the 60% requirement for the site. At our Sunnyvale campus, Tuesdays and Thursdays are the key days where we encourage on-site presence to engage in events and on-site activities.

• Own and improve build-system workflows in our Bazel-based monorepo, including build rules, test execution, dependency management, caching, and build diagnostics.
• Improve CI performance, reliability, and observability, including failure diagnostics, flaky-test handling, and pipeline maintainability.
• Partner with engineering and research teams to identify and remove friction in local development, builds, tests, CI, release workflows, and tooling.
• Build and maintain internal tools, automation, and self-service workflows that reduce repeated manual effort for engineers.
• Diagnose complex build and CI failures across Go, Python, Type Script, and Java codebases.
• Collaborate with Dev Ops and platform engineers on AWS and Kubernetes infrastructure where it intersects with build, test, and delivery workflows.
• Establish practical standards, documentation, and reusable patterns for build systems, CI pipelines, and developer tooling.
• Take accountability for ambiguous developer-productivity problems and drive them through to measurable improvements.
• Use modern AI coding agents responsibly to explore unfamiliar codebases, investigate difficult failures, prototype solutions, and accelerate tooling work.

These responsibilities summarize the role's primary responsibilities and are not an exhaustive list. They may change at the company's discretion.

• 4+ years of experience working on build systems, CI/CD, or developer productivity / platform tooling.
• 2+ years of hands‑on experience with a large‑scale build system (for example Bazel, Buck, Pants, Gradle, or CMake).
• 2+ years of experience building and maintaining CI/CD pipelines in Git Lab CI, Git Hub Actions,…