Security Architect, AI Infrastructure

Fluidstack; Sacramento (CA); On-site; USD 180,000 - 260,000; Full time

Job summary

Fluidstack is building civilization-scale AI infrastructure and seeks an security-focused engineer to own the frontier attack surface. You will design architectures that isolate model weights, training environments, and interconnects, ensuring end-to-end security from bare metal to scheduler and storage.

You will translate research into practical security controls, lead design reviews, and adapt security posture as hardware evolves.

Qualifications

• Experience securing AI/ML infrastructure and HPC systems.
• Ability to architect isolation across hardware to application layers.
• Proven track record turning research into deployable security.
• Ability to defend design decisions in architecture reviews.
• Knowledge of confidential computing and cryptographic key custody.

Responsibilities

• Own the attack surface for frontier AI compute environments.
• Design reference architectures and security standards for fast iteration.
• Run security design reviews across bare metal to fabric layers.
• Keep workloads defensible against evolving adversaries.
• Track new accelerators and interconnects to anticipate risk.

Skills

AI security

Security architecture

Threat modelling

ML security

Confidential computing

Security engineering

Tools

Hypervisor security

Firmware security

Kernel isolation

Job description

About Fluidstack

We exist to make humanity more free. For most of human history, you farmed or you starved. Technology gave people more time for the things they wanted to do, instead of things they had to do. Powerful AI will be the biggest lever for human choice we've ever built - but only if models are aligned with what humanity actually wants. There are groups building AI who don't share these goals. Whoever deploys frontier compute infrastructure fastest will decide whether AI expands human freedom or shrinks it.

We're singularly focused on delivering 10 to 100s of GWs of compute faster than anyone else, rethinking every layer of the stack. We acquire power, design and build data centers, and operate them - with teams spanning hardware and software. Speed and scale are our key differentiators. Come be a part of building civilization-scale infrastructure for AI.

How We Operate

• Be a barrel.
• Full autonomy. Own things end to end, take on scope without being asked, no permission required to operate outside your core role.
• Insane urgency.
• We drive everything forward as fast as possible.
• Reason from first principles.
• Challenge every assumption. Zero analogy thinking, no egos, the best idea wins.
• Love of the game.
• The frontier of AI is the most interesting problem of our time. We put in long hours at high intensity to push the frontier forward.
• Build something that actually matters.
• If you're going to spend your time, spend it on something that matters to the world.

The Security Team

Examples of key problems the team is working onYou're securing the frontier of AI.

The model weights training on our infrastructure are the most valuable and most targeted artifacts in technology, and we're standing up the compute to hold them faster than anyone ever has. A breach isn't a leak, it's the frontier walking out the door.

Build the entire security program from scratch.

Most leaders inherit someone else's system and spend a career patching it. Here you own it end to end, bare metal to boardroom, as we scale across continents.

Your threat surface is measured in gigawatts.

The customers running on our infrastructure are building the most consequential technology in human history, and being responsible for the physical and logical security of that work makes everything else feel small.

Role Scope

Own the attack surface unique to frontier compute: model weights custody, training environment isolation, accelerator and interconnect security, and multi-tenant boundaries under real adversarial pressure.

Design the reference architectures and standards that security engineering builds to, keeping the seam between design and build clean enough that both sides move fast.

Treat the workload as part of the threat model, and architect environments that stay defensible even when the thing running inside them is the adversary.

Run security design review for the systems that touch training and inference environments, from bare metal and fabric to scheduler and storage.

Track where frontier compute is going (new accelerators, interconnect generations, confidential computing, agentic workloads) and have the architecture ready before it lands.

What We're Looking For

The below is a starting point. We always make space for exceptional people, so if you don't fit this role exactly.

• You've secured AI, ML, or HPC infrastructure where the assets were genuinely worth stealing: lab infrastructure security, supercomputing centers, or research environments that drew nation-state attention.
• You can architect isolation at every layer it exists: hardware, firmware, hypervisor, kernel, container, network fabric, and physical.
• You understand AI compute infrastructure as a system (accelerators, high-speed interconnects, parallel storage, schedulers) and know where each component breaks a classical security assumption.
• You've done original work in systems or ML security, published or shipped, and can turn research into architecture that engineers actually build.
• You defend design decisions in review on their merits, and change them when someone closer to the metal proves you wrong.
• Bonus:
• Confidential computing and attestation depth. Weights custody or cryptographic key custody at scale. A publication record in systems or ML security.

We are committed to pay equity and transparency.

Fluidstack is an Equal Employment Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, national origin, sexual orientation, gender identity, disability and protected veterans’ status, or any other characteristic protected by law. Fluidstack will consider for employment qualified applicants with arrest and conviction records pursuant to applicable law.

You will receive a confirmation email once your application has successfully been accepted. If there is an error with your submission and you did not receive a confirmation email, please email with your resume/CV, the role you've applied for, and the date you submitted your application-- someone from our recruiting team will be in touch.