Network Security Engineer

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

• Extreme ownership. Full autonomy. Own things end to end often taking on scope outside your core role without being asked to get things done.

• Velocity. We drive everything forward as fast as possible.

• 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.

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

• Design and defend the network security architecture across data centers, corp, and cloud: segmentation, firewalls, and east-west controls at gigawatt scale.

• Build network detection: telemetry, flow analysis, and alerting across training fabrics, OT networks, and the WAN.

• Harden the OT and BMS side, where the network touches physical plant, against threats most security teams never see.

• Automate network security controls so new sites inherit the architecture on day one.

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've secured production networks at scale, and you read a packet capture as comfortably as a dashboard.

• You've designed segmentation for environments that mix IT, OT, and high-value compute.

• You've deployed and tuned NDR or flow-based detection that found real intrusions.

• You work infrastructure-as-code: your firewall rules live in a repo, not a GUI.

• You've partnered with network engineering without becoming the department of no.

• Bonus: OT and ICS security. Data center or cloud provider environments. BGP and routing security. Zeek or Suricata.

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 View email address on click.appcast.io 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.