Mechanical Engineer, Demand Management

Fluidstack; Austin (TX); On-site; USD 90,000 - 150,000; Full time

Job summary

Fluidstack in Austin seeks a mechanical systems engineer to advance demand flexibility for data-center cooling, with a focus on dynamic thermal modeling and field validation.

You will work with controls engineers to turn cooling strategies into reliable grid assets, designing setpoints, staging, and storage while validating models in real-world plant tests.

Qualifications

• You've engineered mechanical or HVAC systems for data centers or industrial plants.
• You've modeled thermal systems dynamically, not just at steady state.
• You've run field validation campaigns and reconciled model to measurement.
• You quantify risk in operating terms: degrees, minutes, and margins.
• You work jointly with controls engineers as one system team.

Responsibilities

• Engineer the mechanical side of demand flexibility: cooling systems that ride through load flex without thermal risk.
• Model thermal inertia and headroom: how far and how long the plant can flex, quantified per site.
• Design the mechanical strategies, setpoint moves, staging, and storage, that turn cooling into a grid asset.
• Validate in the field: instrumented tests proving the models before the fleet runs on them.

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.

Role Scope

• Engineer the mechanical side of demand flexibility: cooling systems that ride through load flex without thermal risk.

• Model thermal inertia and headroom: how far and how long the plant can flex, quantified per site.

• Design the mechanical strategies, setpoint moves, staging, and storage, that turn cooling into a grid asset.

• Validate in the field: instrumented tests proving the models before the fleet runs on them.

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 engineered mechanical or HVAC systems for data centers or industrial plants.

• You've modeled thermal systems dynamically, not just at steady state.

• You've run field validation campaigns and reconciled model to measurement.

• You quantify risk in operating terms: degrees, minutes, and margins.

• You work jointly with controls engineers as one system team.

• Bonus: Liquid cooling. Dynamic simulation (Modelica, TRNSYS) or CFD. Thermal storage. Psychrometrics depth.

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.