Last Energy

End-to-end services for small nuclear plants

Senior Mechanical Engineer

Design EngineeringConfirmed live in the last 24 hours

Full-timeAustin, TX, USANo salary listedIn-person

About the Job

Requirements

A bachelor's degree in Mechanical Engineering or a related field is required.
At least 4 years of hands-on mechanical design and analysis experience in high-growth, high-urgency environments; startup or advanced manufacturing experience is preferred.
Proficiency with CAD tools such as SolidWorks, AutoCAD, or equivalent is required.
Expertise in FEA and CFD using software such as ANSYS, LS-DYNA, Nastran, or similar is required.
A strong foundation in materials science, stress analysis, and thermal/fluid systems is required.
Ability to turn concepts into tested prototypes quickly with minimal oversight is required.
Strong communication and collaboration skills, especially when interfacing with executives and cross-functional teams, are required.
A bias toward action, creative problem solving, and the ability to own complex problems end-to-end are required.

Responsibilities

Lead the 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 urgent engineering priorities, providing technical insights that 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 FEA and CFD simulation tools 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.
Optimize designs for manufacturability and deployment speed while balancing performance, cost, and scalability.
Drive projects from concept to completion autonomously.

Desired Qualifications

An advanced degree is a plus.
Startup or advanced manufacturing experience is preferred.

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

Last Energy provides decarbonized, reliable, affordable nuclear energy at scale by innovating on the delivery model, not the reactor. By significantly reducing the time and cost of deployment, we are decarbonizing global energy production, increasing access to 24/7 baseload power, and creating a scalable clean energy future for humanity.

About the Company

Last Energy

End-to-end services for small nuclear plants

Last Energy builds small, water-cooled nuclear power plants and provides end-to-end services from planning to maintenance. Its modular reactors use proven designs to supply heat and electricity for industrial uses, including combined heat and power and green-fuel production. It differentiates itself through standardized modules and a full lifecycle service, aiming for faster, lower-cost deployment. Its goal is to make scalable, low-emission nuclear power practical for global markets that support clean technology.

Company size: 51-200
Company stage: Series C
Total funding: $164M
Headquarters: Austin, TX
Founded: 2020

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