Mechanical and Thermal Engineer - Power Electronics

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 Product Engineering Team

Product Engineering builds the power and cooling systems that let Fluidstack deliver gigawatt-scale AI data centers faster and denser than the grid-standard supply chain allows. The SST group is designing solid-state transformers as a core building block of that power architecture.

Examples of key problems the team is working on

• Architect a medium-voltage solid-state transformer that can be manufactured, serviced, and scaled across gigawatt-scale campuses, not just demonstrated in a lab.

• Define the interface between the SST and the MVDC distribution system, including protection, control boundaries, and fault behavior.

• Build a semiconductor and magnetics supply strategy that survives a thin 10kV SiC market over a multi-year horizon.

• Take converter hardware from topology selection through working prototypes on a schedule that data center construction actually depends on.

Role Scope

• Design the mechanical and thermal architecture of the SST block: enclosure, busbars, cold plates, coolant loops, and a layout that fits megawatts of power electronics into a few cubic meters.

• Get heat out of high-voltage parts, including transformers cooled through their insulation, while holding every creepage and clearance distance at tens of kilovolts.

• Size the liquid cooling (glycol loops, heat exchangers, dielectric secondary loops) and close the thermal budget against measured losses at full power.

• Design for manufacture, service, and transport: modules a technician can swap, enclosures rated for outdoor sites, and assemblies a contract manufacturer can build thousands of times.

• Hand off drawings, tolerances, and test fixtures to suppliers, the test lab, and the certification body.

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 designed the enclosure and cooling for high-power converters (MV drives, inverters, SSTs, traction, or EV fast chargers) and shipped them.

• You've laid out high-voltage busbars and conductors to meet creepage and clearance rules in a tight volume.

• You've built liquid cooling for power electronics, from cold plates to heat exchangers, and matched your thermal models to test data.

• You've designed parts for volume manufacture with a contract manufacturer and fixed what broke on the line.

• You've designed hardware for outdoor or industrial sites: dust, humidity, vibration, and shipping loads.

• Bonus: Thermal and flow simulation (CFD, Ansys Icepak, COMSOL). Mechanical CAD (SolidWorks, Creo, NX). Insulation coordination standards (IEC 60664, UL 840). Enclosure ratings (NEMA, IP). Design for manufacture and assembly (DFM, DFA).

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.

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