Senior/Principal Turbomachinery Engineer

About Endurance Endurance is building the world's first modular subsea geothermal power plants, converting vast thermal resources under the ocean into gigawatts of baseload power. Backed by Founders Fund, Felicis, First Round Capital, and Point72 Ventures, our founding team includes veterans from SpaceX, Helion, Blue Origin, and Apple. We have completed multiple deep-ocean deployments to subsea volcanoes and are launching a long-term demonstration project this fall. By leveraging modular design, manufacturing scale, efficient drilling, and latent cooling on the seafloor, we are pioneering a new category of energy that outperforms traditional sources on environmental impact, deployment speed, and cost.

As a Senior or Principal Turbomachinery Engineer at Endurance, you will be the critical technical member of the team responsible for the core of our seafloor power plants. You will lead the design, analysis, and optimization of high-performance turbines and pumps specialized for compact power cycles. This role requires a combination of strong first principles understanding of turbomachinery and a first principles hands-on approach to hardware. You will take turbomachinery designs from initial 1D sizing all the way to testing production designs in subsea deployments.

Lead Aero-Thermal Design: Own the design and optimization of turbines and pumps for power generation cycles. Rapid Iteration: Use 1D/2D modeling tools for rapid sizing, trade studies, and system-level integration. Numerical Simulation: Conduct high-fidelity 3D CFD analysis and structural FEA to ensure component performance and reliability. Testing & Validation: Lead test campaigns to validate turbomachinery performance, correlate analytical models with experimental data, and identify failure modes. Mechanical Integration: Integrate rotors, housings, bearings, and seals into robust, field-ready assemblies. Tool Development: Establish internal modeling processes, design standards, and documentation to enable the team to scale.

Bachelor’s degree in Mechanical or Aerospace Engineering (Master’s or PhD preferred). 3+ years of experience in the design, analysis, and testing of high speed rotating machinery (pumps, compressors, or turbines). Strong fundamentals in thermodynamics, fluid mechanics, and heat transfer. Experience with CAD software (e.g., Siemens NX) and rapid prototyping. Ability to thrive in a fast-paced, "scrappy" startup environment.

Experience with turbomachinery design tools such as AxStream, CFTurbo etc. Proficiency in CFD and numerical simulation tools (e.g., ANSYS CFX/Fluent, OpenFOAM, or Numeca). Experience with supercritical CO2 or organic Rankine cycle (ORC) turbomachinery. Knowledge of high-pressure seal design and rotor dynamics. Hands-on experience setting up and operating high-speed rotating equipment test rigs. Programming skills (Python, MATLAB, or C++) for automated design optimization and data analysis.   Compensation, Benefits, & Perks As a pre-revenue startup, Endurance Energy offers competitive base salaries and generous equity packages for full-time employees. Final base salary will be determined by an array of factors including internal equity, job-related knowledge, skills, and work experience. A key aspect of our compensation philosophy is that value creation should be aligned with rewards. Right now this means equity is a significant portion of every full-time employee's compensation. As the company matures, there will be continued evolution and changes to the total rewards and total compensation package. What will always be true is that if we win, we win together. Equity is granted to every full-time employee as a meaningful piece of ownership. We believe the people building the company should share directly in the value they create. In addition to a competitive base salary and equity, employees will receive all of our other great