Security Engineer, Offensive Security

Fluidstack; San Francisco (CA); On-site; USD 180,000 - 280,000; Full time

Job summary

Fluidstack is seeking a high-impact security professional to build and lead our offensive security program in San Francisco. You will perform red and purple team operations across cloud, endpoints, and bare metal deployments, testing critical systems and AI-enabled workflows.

You will collaborate with engineering and security teams, write automation in Python/Go, and present actionable risk to leadership. This role offers a fast-paced, high-ownership environment.

Qualifications

• Hands-on experience in red teaming and offensive security operations.
• Expertise in at least two of macOS, Linux, cloud (AWS, GCP, Azure), Kubernetes.
• Ability to chain vulnerabilities into full compromise through novel attack paths.
• Experience running adversary simulations against well-defended environments.
• Proficient in writing quality code in Python, Go, or similar languages.

Responsibilities

• Build Fluidstack's offensive security program from the ground up, including its methodology and tooling.
• Run red and purple team operations emulating advanced threat actors across our cloud infrastructure, endpoints and bare metal deployments.
• Pen test critical systems, including tenant isolation, GPUs, firmware and BMCs, and data center OT.
• Collaborate with security and engineering teams on AI-specific attack scenarios.
• Contribute to AI-assisted offensive testing tools and workflows.
• Present findings to technical and executive audiences with clear, actionable risk.
• Operate on the bleeding edge of AI-enabled offensive activities inside and outside our environments.

Skills

Red team operations

Offensive security

Adversary simulations

macOS

Linux

Kubernetes

CI/CD pipelines

Python

Go

Blue team collaboration

Tools

Python

Go

AWS

GCP

Azure

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.

We hire people who care deeply about this problem space. If that is you, please apply!

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 on

• You'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

• Build Fluidstack's offensive security program from the ground up, including its methodology, tooling, and engagement cadence.




• Run red and purple team operations emulating advanced threat actors across our cloud infrastructure, endpoints and bare metal deployments.




• Pen test critical systems, including tenant isolation, bare metal GPU hosts, firmware and BMCs, and data center OT.




• Partner with security and engineering teams on AI-specific attack scenarios, including agentic systems and other novel AI-enabled risks.




• Contribute to AI-assisted offensive testing tools and workflows.




• Present findings to technical and executive audiences as clear, actionable risk that shapes the security roadmap.




• Live on the bleeding edge of AI-enabled offensive operations inside and outside our environments.

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, tell us where you would.

• You have years of hands-on experience in red teaming and offensive security operations.




• You have deep expertise in at least two of: macOS, Linux, cloud (AWS, GCP, Azure), Kubernetes, CI/CD pipelines.




• You've found novel attack paths and chained vulnerabilities into full compromise.




• You've run adversary simulations against well-defended environments.




• You write quality code in Python, Go, or similar languages.




• You write findings that get fixed and help teams prioritize risk.




• You've worked closely with blue teams.




• Bonus: State-nexus threat models (frontier AI, government, critical infrastructure). Testing AI and ML systems (agentic workflows, model serving). Defensive experience (detection engineering, SIEM, EDR). Hardware and data center attacks (firmware, BMC, OT/ICS). Interest in AI safety and 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 [e-mail] 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.