About the role
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, and Robinhood. We have completed multiple deep-ocean deployments 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 both environmental impact and cost. What you'll be doing As a Senior Mechanical Engineer, you will own critical mechanical systems within our seafloor power plants. These systems must survive high pressure, corrosion, thermal cycling, mechanical loads, and long deployment durations in saltwater environments. You will design and deliver pressure-tolerant structures, thermal systems, fluid interfaces, deployment hardware, and mechanical subsystems that operate reliably on the ocean floor. This role blends rigorous analysis with hands-on hardware development. You will take ambiguous, high-risk mechanical systems including pressure vessels, structural frames, thermal interfaces, fluid systems, and deployment hardware and drive them from first principles to offshore deployment. This role requires deep mechanical intuition and extreme ownership. You will architect systems, design parts, release drawings, build prototypes, run tests, break hardware, and iterate until the system works reliably. If a machine fails on the seafloor, you will feel responsible for fixing it permanently. We are looking for someone who has personally built hardware, debugged mechanical failures in the lab or field, and understands the difference between a clean CAD model and a system operating in a harsh environment. Key
Responsibilities Architect and design critical mechanical systems from concept through offshore deployment Perform first-principles analysis of loads, thermal behavior, sealing strategies, and failure modes Design pressure-tolerant hardware, structural systems, and thermal interfaces for subsea environments Develop robust sealing and corrosion mitigation strategies for long-duration saltwater exposure Design assemblies including pressure housings, structural frames, fluid systems, and deployment mechanisms Create detailed 3D CAD models, drawings, and tolerance stacks for complex hardware Build and test prototypes to validate mechanical performance and uncover failure modes Design and execute qualification tests including pressure testing, fatigue testing, thermal cycling, and corrosion exposure Investigate hardware failures and implement permanent design improvements Work directly with fabricators and suppliers to build hardware quickly and correctly Collaborate with electrical, drilling, and subsea systems teams to ensure clean system integration Participate in sea trials and field deployments to validate hardware performance
