Software Engineer, Host Assurance

About the Team Security is foundational to OpenAI’s mission to ensure that artificial general intelligence benefits all of humanity. The Security organization protects OpenAI’s technology, people, and products by building and operating deeply technical systems that must work reliably at massive scale. Our work underpins OpenAI’s commitments around safety, privacy, and security across research, products, and emerging platforms. The Host Assurance team exists to make bare metal and VMs dependable & scalable foundations for OpenAI: secure by default, verifiable in practice, and resilient across providers and operating models. We operate at the trust boundary between hardware and cloud-scale orchestration, ensuring that hosts are eligible to safely run workloads with predictable security properties and auditability. About the Role OpenAI is seeking a Software Engineer, Host Assurance to build and operate the services, APIs, and host software that establish and maintain trust in our compute infrastructure. You will own production software from design and implementation through testing, rollout, observability, and operation. Your work will support capabilities such as machine identity, certificate issuance and enrollment, secure bootstrap, and host attestation across bare-metal and VM environments. Success in this role requires strong technical judgment, the ability to reason across software and host-system boundaries and learn unfamiliar parts of the stack, and a practical mindset for building systems that are secure, reliable, and usable in fast-moving production environments. The systems you build will sit on the critical path of OpenAI’s frontier infrastructure investments and will directly shape how large amounts of compute are brought online - securely, responsibly, and at global scale - underpinning long-lived commitments around privacy, security, and reliability. You will partner closely with infrastructure, research, and confidential computing initiatives—including novel hardware platforms and emerging deployment models– to make the secure path the easiest path. This role is well suited for engineers who enjoy working across trust services, operating systems, hardware and firmware validation, and infrastructure security, and who are excited by ambiguous, high-impact problems at the boundary of hardware and large-scale systems. In this role, you will: Design, build, and operate components of the Host Assurance platform that establish trust in both bare-metal & VM hosts before they are eligible for production use. Help ensure hosts are verifiably trustworthy from delivery and installation through secure bootstrap and readiness to join orchestration systems. Build and improve systems such as machine identity, certificate issuance and enrollment, HSM-backed or key-management-backed trust services, host attestation, measurement, and baseline verification tooling. Validate delivered hardware and firmware against vendor claims and continuously detect and manage drift over time. Eliminate insecure bootstrap patterns while preserving deployment throughput and operational reliability. Partner with provisioning, fleet, and orchestration teams to deliver paved paths where the secure approach is the easiest approach. Own software components through implementation, operational readiness, launch, and ongoing operation. Define readiness criteria, validate behavior under load and failure, establish monitoring and actionable alerts, plan staged rollouts and tested recovery procedures, and maintain runbooks. Use production experience to improve reliability and reduce operational burden. Participate in production support via oncall rotation. Help define observable, testable security properties for host platforms and improve the telemetry and validation needed to enforce them in practice. Work across different deployment models and provider boundaries while maintaining a consistent bar for host trust outcomes. You might thrive in this role if you: Have strong software engineering experience building and operating reliable production systems at scale. Bring depth in distributed systems, backend or platform engineering, operating systems, or infrastructure security. Experience with PKI, HSMs, machine identity, attestation, secure boot, or hardware security is valuable but not required. Can reason across services, APIs, and host software, and learn the boot, firmware, and hardware trust mechanisms relevant to your work. Apply sound judgment to trust boundaries, correctness, and safe failure behavior. Have experience writing production quality code and ability to reason clearly about failure modes, operational safety, and long-term maintainability. Have experience supporting critical production systems at scale, such as being on-call. Balance rigor with pragmatism, and care about making strong security controls deployable in real-world environments. Are self-directed, low ego, and willing to work across disciplines to so