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Fluidstack is building civilization-scale compute infrastructure for AI, with a focus on deploying 10–100s of gigawatts of compute faster than anyone else. The company rethinks every layer of the stack, from power acquisition and data center design to hardware and software operations.
The Thermofluids R&D team is tackling some of the most ambitious thermal engineering challenges in the industry: rejecting more than 10 gigawatts of heat starting immediately, designing and building custom cooling machines (compressors and chillers) that the merchant market cannot supply at scale, and owning every thermofluids problem across the fleet—from working fluid and cycle architecture to two-phase heat transfer at the chip level and thermal energy storage.
As Test Engineer, R&D, you will own the complete test program that takes compressors from first spin on the stand through validated performance mapping. Your responsibilities include:
- Specifying and standing up test cells from an empty bay: motor test bench, high-pressure gas loop, load bank, and all instrumentation.
- Defining the measurement chain and uncertainty budget so that claimed performance metrics (isentropic efficiency, COP) withstand external scrutiny.
- Writing test plans, interlocks, and abort criteria for machines operating at speeds and pressures where failure is energetic and dangerous.
- Turning test data into design changes on a weekly cadence, sitting inside the design loop rather than reporting into it.
- Collaborating closely with the design team, using data to drive hardware decisions.
Fluidstack operates with full autonomy, insane urgency, first-principles reasoning, and a focus on building something that matters. You will be expected to own things end-to-end, take on scope without being asked, and operate at high intensity.
REQUIREMENTS:
- You have commissioned a test stand from a bare bay, including instrumentation, calibration, shakedown, and first-article validation.
- You have deliberately taken a machine to failure and had it instrumented well enough to understand exactly why it failed.
- You have owned an uncertainty budget and can articulate what your measurements are actually worth.
- You have written interlock and abort logic that kept people safe around stored energy, high pressure, or high speed.
- You have disagreed with a design team about what data showed, and the data won.
- You have carried a failure investigation to root cause that changed hardware, rather than closing paperwork with a plausible story.
- Bonus experience: propulsion and engine test (hot fire, spin pit, green run); rotating machinery test (compressors, turbines, motor test benches); high-pressure gas loops and pressure-rated test rigs; data acquisition and rig control (LabVIEW, NI, PLC-based stands); thermal and refrigeration performance testing (COP mapping, calorimetry).
