Thermal Fluids Engineer at Endurance Energy Seattle, WA

Thermal Fluids Engineer job at Endurance Energy. Seattle, WA.

Endurance is developing modular seafloor geothermal power plants that harness the vast thermal energy beneath the ocean floor to provide gigawatts of clean, reliable energy. We’re addressing the critical power bottleneck facing AI infrastructure development while creating a path toward energy independence and decarbonization across the globe.

Backed by premier venture capital firms including First Round Capital and Point
72 Ventures, our exceptional founding team includes veterans from Space

X (Dragon and Starship programs) and Neuralink with specialized expertise in complex thermal and fluid systems.

We’re seeking a talented Thermal and Fluids Systems Engineer to join our team at our headquarters in Seattle where you’ll help design and develop the core power cycle for our revolutionary seafloor generators.

As a Founding Thermal and Fluids Systems Engineer at Endurance, you’ll be a key early member of our team building the power generation cycle at the heart of our subsea geothermal power plants. You will rapidly design, test, and optimize the components of a compact power cycle playing a pivotal role in bringing this novel energy system from concept to reality.

This role focuses primarily on systems engineering and integration of proven components into robust field‑ready systems, but also requires flexibility, creativity, and an entrepreneurial mindset essential to an early‑stage startup. You’ll work across multiple technical domains and help shape the foundation of our energy systems as the company scales.

Your first major project will be the design, build, and testing of a 100 kWe compact power cycle at our site in Seattle. This full‑scale loop will validate the performance and reliability of our core power generation technology in a controlled land‑based environment before it is packaged for subsea deployment.

• Lead the thermal‑fluid design of new power cycle architectures and components including turbines, heat exchangers, pumps, condensers, and piping systems.
• Assemble, operate, and validate a 100 kW scale thermodynamic power cycle test loop.
• Design and build test rigs for component and system testing.
• Carry out detailed analysis and component optimization using numerical simulation tools.
• Support the design of other mission‑critical systems such as geothermal and hydrothermal heat exchangers and deep‑sea vehicles.
• Support business development activities including supplier meetings, technical presentations, and customer interactions.
• Help establish system engineering and modelling tools, processes, and documentation for future team growth.

• Bachelor’s degree in mechanical, aerospace, or related engineering discipline (preferably with a master’s).
• 3 years of experience in thermal and fluid systems modeling and/or design.
• Experience designing, building, testing, and deploying test rigs for system validation.
• Ability to act and execute in a scrappy and entrepreneurial manner.
• Strong problem‑solving skills and attention to detail.
• Excellent communication and teamwork abilities.

• Strong background in the design and analysis of thermal‑fluid systems.
• Experience designing turbo machinery (pumps, compressors, or turbines).
• Proficiency in developing low‑order modeling tools for system sizing, trade studies, and rapid design iteration, including transient system modeling.
• Skilled in CFD and numerical simulation tools for fluid flow and heat transfer analysis (e.g., ANSYS Fluent, OpenFOAM).
• Hands‑on experience setting up instrumentation and operating experimental test rigs and facilities.
• Familiarity with basic mechanical design and manufacturing processes, including CAD‑based design and prototyping.
• Bonus:
  Experience in marine systems, power generation, geothermal energy, or supercritical fluids.

• Global Fieldwork: Travel to fascinating deployment sites along oceanic ridges in locations such as the Pacific Northwest, Hawaii, Iceland, Japan, New Zealand, and the Azores.
• Hands‑on
  
  Experience:
  
  Participate in sea trials and deployment operations in partnership with leading oceanographic institutions.
• Cutting‑Edge Development: Work with technology that spans high‑power electronics, marine systems, and clean energy.
• Impact‑Driven Work: Help solve one of the world’s most pressing challenges—clean, reliable power generation.
• Competitive Compensation: Comprehensive salary and equity packages.
• Benefits: Vision, Dental, Health insurance coverage.
• Dive Certification: Company‑sponsored recreational dive certification.
• PTO: Unlimited (with advanced notice).

This role has a compensation range of $150,000 – $200,000 base salary.

Endurance is an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees.

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