Senior Power Electronics Engineer, Thermofluids

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.

Examples of key problems the team is working on

• Reject 10s of GW of heat, starting now. Fluidstack is targeting 10s of GW of compute over the next two years. Every watt of it becomes heat that has to go somewhere, and no cooling team has ever been asked to open at that scale rather than grow into it.
• Design and build the machines, because nobody can supply them. The merchant compressor market cannot deliver at this rate, and the vendor base behind today’s chillers will not scale to gigawatts. We are taking compressor and chiller design in house, working on machine architectures nobody sells today, and going from blank sheet to production faster than this industry thinks is possible.
• Own every thermofluids problem behind the fleet, not just the chiller. Working fluid and cycle architecture, heat exchangers at a scale that dominates the cost of the plant, two-phase heat transfer at the chip, and thermal energy storage. All of it is open, and whatever this team lands gets built thousands of times.

Role Scope

• Own the electrical design of the machine’s power path: the DC bus, the inverter, the motor drive, and the amplifiers driving the magnetic bearings around the rotor.
• Specify and integrate the drive for a high-speed hermetic motor, including the switching, thermal, bearing-current and insulation questions that follow from running a machine fast.
• Design the power and protection scheme for the test benches and the load bank, so a machine can be run to full rating and its output absorbed or regenerated.
• Take the electrical scope through EMC, harmonics and arc flash to an installation that is safe to work on and safe to sign off.
• Own electrical safety in the test cell, including the procedures the technicians and test engineers work to around live buses and stored energy.

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

• 10+ years of experience in power electronics and motor drive design, including high-power converters, high-speed motor drives, and electrical safety for test and production systems.
• You’ve designed a high-power converter or motor drive that got built, and you were there the first time it drove a real load.
• You’ve integrated a drive with a motor somebody else designed, and dealt with what the drive then did to the machine and to everything sharing the bus.
• You’ve chased an EMC, harmonic or bearing-current problem to its actual cause instead of adding a filter and hoping.
• You’ve written electrical safe work practices and then enforced them on people who found them inconvenient.
• You’ve powered up a test cell or a first-of-a-kind installation, and you were the one who decided it was safe to close the breaker.
• You're comfortable with regular travel: expect 25% or more, depending on business needs.
• Most of our engineering team, stakeholders, and work are based in Austin, TX, and we value working in person. We have a strong preference for Austin and run a hybrid model, but we're open to other locations for the right role and candidate.
• Bonus: High-speed and magnetic-bearing drive systems. Electric propulsion and aerospace power systems (eVTOL, satellite EPS, electric pump-fed engines). 800 V class DC architectures and wide-bandgap devices (SiC, GaN). Test cell power and safe practice around energized work (test benches, load banks, regenerative drives).

We are committed to pay equity and transparency.