Magnetics Engineer - Medium-Frequency Transformers

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 medium-frequency transformer at the heart of every SST cell: hundreds of kilowatts at tens of kilohertz, insulated for tens of kilovolts DC to ground.

• Choose core materials, winding structures, insulation, and liquid cooling that balance loss, size, and cost across thousands of units.

• Prove each design on the bench with hi-pot, partial-discharge, impulse, and thermal-cycling tests, and set the acceptance tests every production unit must pass.

• Review vendor transformer designs during co-development and sign off on their insulation margins before we commit to volume.

• Turn the design into a part a supplier can wind, pot, and test at volume, and qualify a second source.

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 and built high-frequency transformers or inductors for power converters at tens to hundreds of kilowatts.

• You've designed insulation for medium-voltage magnetics and run hi-pot, partial-discharge, and basic impulse tests yourself.

• You've used FEA to predict losses, leakage inductance, and hot spots, then matched those predictions to measured data.

• You've pulled heat out of a winding through its insulation system, by cold plate or liquid, without creating partial discharge.

• You've taken a magnetic component from prototype to volume production with an outside supplier.

• You've traced a test or field failure to its root cause in the insulation, core, or winding.

• Bonus: Core materials (nanocrystalline, ferrite). Solid and cast insulation (epoxy, silicone potting). Magnetics FEA (ANSYS Maxwell, COMSOL). Integrated leakage design for resonant converters (LLC, DAB). Transformer and insulation standards (IEC 61558, UL 1446).

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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