Staff Build Engineer

SandboxAQ is a high-growth company delivering AI solutions that address some of the world's greatest challenges. The company’s Large Quantitative Models (LQMs) power advances in life sciences, financial services, navigation, cybersecurity, and other sectors.

We are a global team that is tech-focused and includes experts in AI, chemistry, cybersecurity, physics, mathematics, medicine, engineering, and other specialties. The company emerged from Alphabet Inc. as an independent, growth capital-backed company in 2022, funded by leading investors and supported by a braintrust of industry leaders.

At SandboxAQ, we’ve cultivated an environment that encourages creativity, collaboration, and impact. By investing deeply in our people, we’re building a thriving, global workforce poised to tackle the world's epic challenges. Join us to advance your career in pursuit of an inspiring mission, in a community of like-minded people who value entrepreneurialism, ownership, and transformative impact.

The Cybersecurity Group at SandboxAQ is looking for a Staff Build Infrastructure Engineer to build the engineering platform for AQtive Guard, our groundbreaking Cryptographic Posture Management and AI Security Posture Management products. As we deploy globally with major organizations like top-tier financial institutions and government agencies, the speed, quality, and security of our software delivery are critical to our success.

As our engineering team scales, waiting for builds is not an option. We are looking for an expert who treats the Build System and CI as a Product. In this role, you will own the end-to-end delivery pipeline, migrating our services to a hermetic Bazel monorepo backed by a massive, Kubernetes-native remote execution cluster (e.g., BuildBarn/EngFlow).

You will engineer a distributed compilation platform that makes builds instantaneous and reproducible. You will write the Starlark rules, the control planes, and the Kubernetes operators that allow hundreds of engineers to ship code safely and rapidly.

We are looking for a systems engineer who can dig into the details of build issues and the high-level design of distributed systems. If you are passionate about eliminating "it works on my machine" forever, this role is for you.

• Architect the Build Plane: Lead the design and implementation of a high-performance, hermetic build system using Bazel. You will optimize the graph for massive concurrency and incremental correctness.

• Scale Remote Execution: Design, deploy, and tune a Remote Build Execution (RBE) cluster (e.g., BuildBarn) running on Kubernetes. You will manage the distributed cache and worker pools to handle spikes in compilation demand across thousands of cores.

• Engineer Developer Tooling: Write custom CLI tools and IDE plugins that abstract the complexity of the build system. You will create the "Golden Path" that allows product engineers to spin up hermetic test environments with a single command.

• Modernize CI/CD: Move beyond brittle shell scripts. You will treat pipelines as software, using GitOps (ArgoCD) to orchestrate testing workflows that are dynamic, testable, and versioned.

• Optimize the Inner Loop: Obsessively profile and reduce build latency. You will analyze critical paths, debug cache misses, and write custom Bazel rules to ensure that feedback loops remain under seconds, not minutes.

• Drive Technical Culture: Mentor the wider engineering team on monorepo best practices, dependency management, and hermeticity. You will set the standard for how code is built, tested, and released.

• 5+ years of Software Engineering experience with a focus on Developer Infrastructure, Build Engineering, or SRE.

• Deep expertise in Bazel. You can write custom Starlark rules/macros, debug toolchain hermeticity issues, and explain the difference between input pruning and output caching.

• Systems Programming Proficiency (Go/Kotlin/Python). You can write high-performance CLI tools, indexers, or sidecars to augment the build experience.

• Experience with Remote Execution. You have operated RBE systems (BuildBarn, EngFlow, or RBE) at scale and understand the underlying gRPC protocols.

• Kubernetes Fluency. You understand how to schedule ephemeral build workloads on K8s and have experience with auto-scaling based on queue depth.
  

• Experience migrating legacy codebases (Maven, Gradle, Make) to Bazel.

• Contributions to the open-source Bazel ecosystem or rules (e.g., rules_go, rules_docker).

• Experience for toolchain management.

• Knowledge of compiler internals and linkers.

• Experience building ephemeral test environments

We offer a comprehensive and competitive benefits package designed to support your health, financial well-being, and life outside of work.

• Compensation: Competitive base salary, performance-based incentives or bonuses (where applicable), and equity participation.

• Benefits: Comprehensive medical, dental, and vision coverage for employees and dependents with generous employer premium contributions, retirement savings with company matching, paid parental leave, and inclusive family-building benefits.

• Work-Life Balance: Flexible paid time off, company-wide seasonal breaks, and support for flexible work arrangements that enable sustainable performance.

• Career Development: Opportunities for continuous learning and growth through on-the-job development, cross-functional collaboration, and access to internal learning and development programs.

We are committed to fostering a culture of belonging and respect, where diverse perspectives are actively sought and valued. Our multidisciplinary environment provides ample opportunity for continuous growth - working alongside humble, empowered, and ambitious colleagues ready to tackle epic challenges.

Equal Employment Opportunity: All qualified applicants will receive consideration regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity, or Veteran status.

Accommodations: We provide reasonable accommodations for individuals with disabilities in job application procedures for open roles. If you need such an accommodation, please let a member of our Recruiting team know.

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