Jobs in the United States

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Added 5 hours ago
Entry-level Aerospace/Electrical/Mechanical Engineer
Frontera Space
Cedar Park, TX
Join Frontera Space at an early stage and help create a transformational aerospace platform designed to change how high-speed aircraft and access-to-space systems are developed,…
Added 6 hours ago
High Speed Systems Engineer
Dynetics, Inc
Huntsville, AL · King Of Prussia, PA · San Diego, CA · Arlington, VA · Beavercreek, OH
Leidos Defense Systems is seeking a highly motivated Systems Engineer who loves collaboration and being a part of something big, to join our team. This role drives the implementation of…
Added 7 hours ago
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Systems Engineer
Actalent
Saint Paul, MN
- $65 to $95 USD / hour
Job Title: Senior Systems Engineer Job DescriptionThe Senior Systems Engineer will provide technical leadership for the design, development, and optimization of advanced hypersonic test…
Added 12 hours ago
Propulsion Test Engineer
Voyager Technologies, Inc.
Pueblo, CO
The Propulsion Test Engineer for Propulsion Systems is responsible for independently planning, executing, and documenting static fire tests for solid and liquid rocket motors throughout the…
Added 17 hours ago
Powertrain Quality & Reliability Engineer – Transmission Systems
HTC Global Services Inc
Livonia, MI
Serve as a product development engineer responsible for 10-speed rear-wheel-drive (RWD) propulsion systems and their integration into vehicle spaces.
Added 18 hours ago
Sr. Power Electronics Engineer - BNS Core Systems and Components
Blue Origin Personnel, LLC
Denver, CO
This role is part of Blue National Security (BNS), where our focus is the design, development, and delivery of launch and spacecraft systems for national security missions. Through Blue…
Added 1 day ago
Senior Manufacturing Test Engineering, Propulsion
Anduril Industries
Ashville, OH · Costa Mesa, CA
Every Propulsion Test Engineer is responsible for the full lifecycle of engine testing. You will design and fabricate physical test racks and instrumentation suites, write Python-based test…
Added 1 day ago
Controls Engineer II
Austal USA
Mobile, AL
Responsible for design calculations and drawing development as assigned by the Program Engineer or a Department Engineer III
Added 1 day ago
Vehicle Propulsion Local Product Senior Engineer
JLR
Mahwah, NJ
POSITION: Vehicle Propulsion Local Product Senior Engineer
Added 1 day ago
Vehicle Propulsion Local Product Senior Engineer
United States
POSITION: Vehicle Propulsion Local Product Senior Engineer
Added 1 day ago
Manufacturing Test Engineering, Propulsion
Anduril Industries
Ashville, OH · Costa Mesa, CA
Every Propulsion Test Engineer is responsible for the full lifecycle of engine testing. You will design and fabricate physical test racks and instrumentation suites, write Python-based test…
Added 1 day ago
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Mechanical Engineer, Thermofluids
Fluidstack
Austin, TX · San Francsisco, CA · Los Angeles, CA
- $210,000 to $260,000 USD / year
- Bonus: Vapor-compression and transcritical cycles (chillers, heat pumps, refrigeration). Propulsion and cryogenic fluid systems (feed systems, regenerative cooling, two-phase transport).…
Added 1 day ago
VM
Senior Mechanical Engineer
Volund Manufacturing
Huntington Beach, CA
- $175,000 to $250,000 USD / year
We design propulsion systems for cost, agility, and scale, combining advanced automation, precision manufacturing, and rapid iteration to move from prototype to production at unprecedented…
Added 1 day ago
Propulsion Base Software Sr Core Development Engineer
Stellantis
Auburn Hills, MI
The Propulsion Base Software Core Development Engineer is responsible for contributing to the development of embedded software for EE/core and propulsion control modules. This role involves…
Added 1 day ago
GA
Lead Embedded Systems Engineer
GE Aerospace
Bohemia, NY
- $114,000 to $152,000 USD / year
…and defense sector. Primary focus is on developing advanced, high-speed propulsion engines to support the Department of Defense Modernization Priorities. Our customers and partners include…
Added 1 day ago
VM
Test Engineer
Volund Manufacturing
Huntington Beach, CA
- $130,000 to $160,000 USD / year
We design propulsion systems for cost, agility, and scale, combining advanced automation, precision manufacturing, and rapid iteration to move from prototype to production at unprecedented…
Added 2 days ago
H
Mechanical Engineer
Hermeus
Los Angeles, CA
- $91,800 to $140,250 USD / year
…today. By prioritizing relentless hardware iteration, we deliver high-speed systems at the pace of the modern battlefield. We work with the Department of War to provide the high-speed…
Added 2 days ago
H
Chief Engineer - Airbreathing Propulsion Test
Hermeus
Jacksonville, FL
- $138,550 to $247,250 USD / year
Hermeus is seeking a hands-on, technically rigorous Chief Engineer to lead the expansion of our High Enthalpy Airbreathing Test (HEAT) facility in Jacksonville, Florida. This is a…
Added 2 days ago
SR
Senior Digital Engineering (DE) Integration & Oversight Engineer
Scientific Research Corporation
Alexandria, VA
- $228,100 USD / year
Seeking a highly skilled Senior Digital Engineering (DE) Integration & Oversight Engineer to provide Systems Engineering and Technical Assistance (SETA) support to the Department of War…
Added 2 days ago
Build Reliability Engineer II
Relativity Space
Long Beach, CA
The Reliability team at Relativity Space ensures quality is built into every stage of the Terran R design and production process, embedding reliability from the very beginning. The team…
Added 2 days ago
IL
Lead Embedded Systems Engineer
Innoveering, LLC
United States
- $114,000 to $152,000 USD / year
…and defense sector. Primary focus is on developing advanced, high-speed propulsion engines to support the Department of Defense Modernization Priorities. Our customers and partners include…
Added 2 days ago
D489 Construction Support Component Engineer (Senior / Specialist)
General Dynamics Electric Boat
New London, CT
The selected candidate will provide design and deck plate support for main propulsion system (MPS) equipment (e.g., main propulsion controls and ACC subcomponent, main propulsion motor…
Added 2 days ago
Electrical Engineer (Starship Avionics)
SpaceX
Starbase, TX · Brownsville, TX
Experience with circuit board layout, especially for switching power converters or high-speed digital applications where signal integrity is critical
Added 2 days ago
Mechanical Engineer
Tiberius Aerospace Inc.
Newport Beach, CA
We’re looking for a Mechanical Engineer to design, build and test hardware for Tiberius’s aerospace and defense systems. You’ll turn requirements into practical mechanical designs, support…
Added 2 days ago
Intern - Mechanical Design Engineer
NORTH WIND SYSTEMS LLC
Ronkonkoma, NY
…development, and flight testing. Our team drives innovation in high-speed aerodynamics, propulsion systems, and mission-critical components, supporting every phase of hypersonic programs -…

Fluidstack

Mechanical Engineer, Thermofluids

Austin, TX, United States
San Francsisco, CA, United States
Los Angeles, CA, United States

$210,000 to $260,000 USD / year

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Job details

Pay: $210,000 to $260,000 USD / year
Experience: 10+ years of experience in thermofluids engineering, including thermodynamic cycle modeling, heat exchanger design, and high-pressure fluid system design.
Posting language: English
Posted: Oct 29, 2026

Original 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.

THE THERMOFLUIDS R&D TEAM

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

Define what the machine has to be, owning the cycle model that sets the working fluid and the pressures, temperatures and flows the compressor, turbine and exchangers are designed against.
Design heat exchangers with surface areas running into millions of square meters, among the largest single drivers of a data center’s physical footprint.
Design the fluid system around the machine: piping, valves, headers, relief and isolation, sized against the pressure-drop budget the cycle can afford and the pressures the fluid actually runs at.
Run the trades that decide the machine: air-side temperature rise, face velocity and subcooling. Derive the operating points from coupled exchanger ratings rather than asserted approach temperatures, so infeasible designs get caught in the model instead of in hardware.
Take the cycle predictions onto the test stand and reconcile them against measured COP, then say plainly where the model was wrong.

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 https://jobs.ashbyhq.com/fluidstack/05c2e69c-42f9-4fcb-9cf0-a467aaf98f1c.

10+ years of experience in thermofluids engineering, including thermodynamic cycle modeling, heat exchanger design, and high-pressure fluid system design.
You’ve built a thermodynamic cycle model from fluid properties up and defended its assumptions to someone actively trying to break it.
You’ve sized real heat exchangers against published correlations, and you’ve caught a case where the correlation belonged to a different geometry than the one in front of you.
You’ve calibrated a model against a machine datasheet or test data and reported the gap honestly rather than tuning until it disappeared.
You’ve written the analysis that changed a design decision, in a form that people who never ran the code could read and act on.
You’ve sized a relief path and been the one who signed off that the system was protected.
You’ve held a result open when it was still open, instead of closing it early to be helpful.
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: Vapor-compression and transcritical cycles (chillers, heat pumps, refrigeration). Propulsion and cryogenic fluid systems (feed systems, regenerative cooling, two-phase transport). Piping and relief design for high-pressure fluid systems. Real-gas properties and two-phase heat-transfer correlations (CoolProp, REFPROP, Cavallini, Gnielinski, Wang). Data center thermal architecture (CDUs, dry coolers, direct-to-chip).

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.

Applicant Privacy Notice https://fluidstack.io/legal/applicant-privacy-notice AI Screening Notice https://fluidstack.io/legal/ai-screening-notice Ashby Bias Audit https://fluidstack.io/legal/ashby-bias-audit

You will receive a confirmation email once your application has successfully been accepted. If there is an error with your submission and you did not receive a confirmation email, please email careers@fluidstack.io with your resume/CV, the role you've applied for, and the date you submitted your application-- someone from our recruiting team will be in touch.

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