Director - Mechanical Engineering

Thea Energy is leveraging recent breakthroughs in stellarator physics and engineering to create a faster and simpler approach to commercializing fusion energy. The company is reinventing the stellarator using computer-controlled arrays of planar coils thereby replacing the intricate, complex modular magnets required in all other stellarator architectures. Thea Energy is on a mission to create a limitless source of zero emission energy for a sustainable future.

Thea Energy is looking for an experienced, highly motivated Director - Mechanical Engineering to join its rapidly growing team. You will have ownership of the mechanical design and development of primary and secondary components and subsystems in the development of Thea Energy's integrated stellarator fusion systems. You will be responsible for structural and thermomechanical design, manufacturability, development, and commissioning of these components.

You will drive requirements definition, design trades, and integration across disciplines. You will build and lead an integrated team drawing from disciplines including mechanical design, structural and stress analysis, thermal/fluids analysis, materials engineering, manufacturing and fabrication engineering, nuclear engineering, and vacuum systems engineering.

The Thea Energy team is comprised of driven, creative, and fun individuals passionate about solving complex problems.

Key Responsibility Areas

• Own the technical baseline for primary and secondary mechanical fusion systems, including requirements, design, development, analysis, verification, though manufacturing, commissioning, and operation.
• Drive system-level trades across relevant performance domains (e.g. thermal, structural, electromagnetic, nuclear, vacuum, cryogenic).
• Maintain accountability for the key performance metrics that define system success.
• Define and enforce interface controls.
• Work with core system-level development teams to define requirements.
• Lead system design and development, addressing the complex 3D non-axisymmetric geometry unique to stellarators.
• Drive disciplined design trades balancing performance, manufacturability, and schedule.
• Own the analysis campaigns required to demonstrate system feasibility and adequate margin under all operating conditions (normal operation, off-normal events, transients).
• Partner with manufacturing and fabrication engineering to ensure all components can be built, inspected, and assembled within realistic tolerances.
• Address stellarator-specific fabrication challenges driven by non-axisymmetric geometry and tight tolerance requirements.
• Own the assembly sequence and integration plan for systems within the overall machine build.
• Serve as the system-level integrator for system interfaces.
• Work with Systems Engineering & Configuration Management to define and maintain interface control documents, requirements flow down, and configuration baselines.
• Coordinate across engineering tools to establish CAD/CAE/PLM workflows and simulation infrastructure.
• Make scope and schedule trade-offs, escalating risks and decision points with clear technical rationale.
• Build, lead, and develop the integrated engineering team, spanning multiple disciplines.
• Define work packages, priorities, and deliverables across the team.
• Maintain technical risk registers and drive mitigation plans to closure.
• Build and maintain a technically rigorous team culture, setting expectations for analysis quality, design rigor, and documentation standards.

Ideal Experience & Skillsets

• 15+ years of experience in mechanical engineering, nuclear engineering, or a closely related field, with significant time spent on large-scale, high-performance hardware systems.
• Deep technical knowledge of at least two of the following: structural analysis, thermal-hydraulic analysis, vacuum system design, cryogenic engineering, nuclear engineering, high-heat-flux component design, manufacturing engineering.
• Demonstrated experience managing complex, multi-disciplinary hardware development programs from concept through fabrication and test.
• Strong understanding of materials behavior and manufacturing processes for demanding mechanical systems.
• Proficiency with engineering tools: CAD (NX preferred), FEA (ANSYS preferred), and PLM systems.
• Bias toward ownership: you take accountability for outcomes, not just activities.
• Ability to make system-level decisions under uncertainty and defend them with engineering rationale.
• Effective at leading integrated, multi-disciplinary teams through clarity of scope and technical credibility.
• Comfort with ambiguity and pace of a startup building first-of-a-kind hardware.
• Strong written and verbal communication: you can present system status, risks, and trades to executives and to the engineering team with equal effectiveness.
• Track record of building and leading high-performing technical teams.
• Exceptional work ethic and a bias toward action.
• Innate desire to learn, innovate, and challenge assumptions, including your own.
• At least a bachelor's degree in mechanical engineering, aerospace engineering, physics, or related fields.

Company Benefits

• Salary range $135,000-$235,000
• Comprehensive health benefits (e.g. medical/dental/vision)
• Employee equity stock options
• 20 days PTO

It's not necessary to meet all of the skillsets outlined above. Please feel free to send us a note and tell us why you would still be a great fit for this role or Thea Energy.

Diversity and Inclusion

Thea Energy is an equal opportunity employer committed to creating a company of diverse backgrounds. By creating a diverse environment, we will bring new ideas and approaches to solving some of the world's hardest (and most important) problems. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, gender, sexual orientation, gender identity or expression, national origin, family or marital status, age, disability, veteran's status, or other characteristic protected by applicable laws and regulations.

We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us.