Senior Mechanical Engineer

Last Energy is a pioneering US technology company deploying next-generation modular nuclear power plants. With projects underway in the US and UK, we’re transforming how nuclear energy is designed, built, and delivered-through high-throughput manufacturing, efficient supply chains, and rapid deployment strategies.

As a Senior Mechanical Engineer at Last Energy, you’ll work directly with the CEO and core leadership team to drive forward the most critical mechanical and system-level challenges shaping our fleet-wide product. This is a role for builders, doers, and innovators who thrive in a fast-paced, hands-on environment where decisions are made quickly and your ideas directly shape the product.

Key Duties & Responsibilities

• Lead design and execution of critical mechanical systems and components that enable scalable, manufacturable nuclear power plants
• Collaborate daily with the CEO and executive team on the company’s most urgent engineering priorities-your technical insights will directly inform product strategy and deployment timelines
• Drive concept development, detailed CAD modeling, and rapid prototyping of novel industrial systems
• Perform structural, thermal, and fluid analyses using advanced simulation tools (FEA, CFD) to validate and optimize designs
• Design and analyze complex mechanical assemblies
• Integrate mechanical, electrical, and control systems into cohesive plant-level solutions
• Oversee prototype fabrication, assembly, and testing, both in-house and with external partners
• Develop fixtures, tooling, and manufacturing aids to streamline build and test operations
• Continuously optimize designs for manufacturability and deployment speed, balancing performance with cost and scalability
• Operate autonomously, driving projects from concept to reality in a startup culture that values speed, ingenuity, and accountability

Qualifications

• Bachelor’s degree in Mechanical Engineering or a related field (advanced degree a plus)
• 4+ years of hands-on mechanical design and analysis experience in high-growth, high-urgency environments (startup or advanced manufacturing preferred)
• Deep proficiency with CAD tools (SolidWorks, AutoCAD, or equivalent)
• Demonstrated expertise in FEA and CFD using software such as ANSYS, LS-DYNA, Nastran, or similar.
• Strong foundation in materials science, stress analysis, and thermal/fluid systems
• Proven ability to turn concepts into tested prototypes quickly, with minimal oversight
• Exceptional communication and collaboration skills, especially when interfacing with executives and cross-functional teams
• A bias toward action, creative problem solving, and the drive to own complex problems end-to-end