AI Infrastructure Security Engineer

OUR MISSION Rebuild how the world works, to make institutions work better for the people they serve. ABOUT BRAIN CO. Brain Co. builds AI-native operating systems for large, regulated institutions. Each system is built for a specific industry, powered by agents that push real workflows forward. Underneath it all is Atlas, our proprietary platform that keeps customers in control, secure by design, and never locked into one model. WHY NOW Brain Co. is entering its next phase of production deployments on a national scale with an elite team built from Palantir, Google, Meta, and Nvidia, and a growing footprint across government, insurance, health, and financial services. Joining now means shaping both the company and a new category of applied AI. Every project here ships to production and is expected to create measurable customer value and impact. You'll work alongside exceptional peers on some of the hardest problems in applied AI. It’s the kind of work you'll still be proud of in ten years from now. ABOUT THE ROLE: As our Security Engineer, Infrastructure, you'll secure the platform layer end-to-end including cloud infrastructure, Kubernetes, identity, networking, and the systems that AI runs on. This is a hands-on builder role. You'll write code, ship infrastructure, and work shoulder-to-shoulder with our infra team as a true engineering partner, not a reviewer. It's a high-ownership role for someone who wants to build secure-by-default infrastructure from first principles, and grow the function as the company scales. You'll also be thinking a step ahead about security in an AI-native environment, where agents write code and operate inside developer and production workflows, while staying grounded in the core work of cloud, Kubernetes, identity, and networking. WHAT YOU’LL WORK ON: - Build the security foundations of our AI platform: identity, isolation, secrets management, and access control across cloud and Kubernetes environments. - Harden infrastructure end-to-end from cloud networking and service meshes to CI/CD pipelines and the data and model pipelines powering Brain Co's AI capabilities work. - Implement Zero Trust principles and machine identity across workloads; short-lived credentials, least-privilege access, and encrypted service communication. - Protect customer data and the agent workloads running on our platform. Design secure execution environments and data access pathways for code and actions taken by agents on our systems. - Build security guardrails directly into infrastructure and deployment workflows using Infrastructure-as-Code (Terraform) so security scales with the platform. - Own threat modeling across infrastructure layers—identifying and remediating risks before they become incidents. - Own security for Brain Co's forward-deployed infrastructure — designing and hardening bespoke VPCs and customer-environment deployments where every engagement brings its own unique attack surface. - Partner with platform, infra, product, and ML teams to ship code and infrastructure together as a true partner so engineers move fast with secure-by-default systems. YOU MIGHT BE A GREAT FIT IF YOU: - Have 5+ years of experience in security engineering, infrastructure, or SRE with hands-on experience building or securing production systems at scale. - Are fluent in cloud security fundamentals (IAM, networking, KMS, secrets, isolation) across AWS, GCP, or Azure. - Have designed and implemented secure systems end-to-end not just reviewed them after the fact. - Have hands-on experience with Kubernetes, container security, and Linux systems. - Think in terms of threat models, trust boundaries, and failure modes and can translate that into concrete controls. - Enjoy building paved roads and guardrails using Infrastructure-as-Code (Terraform preferred) so the whole team moves faster safely. - Have experience with authentication and authorization systems, secrets management, and cryptography basics. - Are a hands-on builder who is energized by writing code, shipping infrastructure, and partnering directly with infra and platform engineers rather than advising from the sidelines. - Thrive in ambiguous, high-agency environments and want ownership of the infrastructure security function as it grows. BONUS POINTS FOR: - Experience with ML systems or multi-tenant platform isolation. - Familiarity with service mesh and zero-trust architectures. - Proficiency in Go, Python, or a similar language for automation and tooling. WHY JOIN US: - Secure an AI platform operating at the frontier; deployed in governments, hospitals, and critical industries worldwide. - Work on infrastructure security where the attack surface is still being defined — protecting systems built to push AI capabilities forward. - Work alongside senior engineers from Tesla, DeepMind, Databricks, and other top engineering orgs. - Shape how infrastructure security is done from the ground up with real ownership and scope to grow. - Ship fast, learn constantly, and see your work protect production systems used by millions. - Earn competitive compensation and meaningful equity in a high-growth company. BENEFITS - Competitive salary plus equity - Daily lunches - Commuter benefits - 401(k) - Medical, Dental, and Vision - Unlimited PTO