Senior Mechanical Engineer

About Commonwealth Fusion Systems:  Commonwealth Fusion Systems is on a mission to deliver the urgent transition to fusion energy. Combining decades of research, top talent, and new technologies, we’re designing and building commercially viable fusion power plants. And we're working with policymakers, suppliers, and many others to build the energy industry of the future. We’re in the best position to make it happen. Since 2018, we’ve raised $4 billion of capital, making us the largest and leading fusion company in the world. Now we’re looking for more thinkers, doers, builders, and makers to join us. People who’ll bring new perspectives, solve tough problems, and thrive as part of a team. If that’s you and this role fits, we want to hear from you.
Join the power movement as a Senior Mechanical Engineer We’re looking for a Senior Mechanical Engineer to join our R&D and equipment design team to help build the next generation of thin-film deposition technology. The Senior Mechanical Engineer will be responsible for the design and implementation of advanced R&D equipment and complex machinery. This role requires strong technical expertise, procedural discipline, and the ability to collaborate across engineering and technology functions to ensure safe, reliable, and high-performance equipment. If you enjoy working on complex design problems, mentoring others, and solving problems in a collaborative, fast-paced environment, this is your opportunity to make an impact.

What you'll do:

Lead the design and implementation of advanced R&D equipment for thin film processing, including ownership of key mechanical modules and sub-systems

Lead design reviews for key mechanical subsystems

Generate and maintain interfaces with other engineering subsystems

Report on and be accountable for project progress to stakeholders

Work effectively within a multi-disciplinary team of top scientists and engineers

Mentor engineering staff for effectiveness and delivery of on-time & in-spec outcomes

Get things done: drive projects, consistently deliver, act with speed

What we’re looking for:

Bachelor's degree in Mechanical Engineering or related field (or equivalent industrial experience)

8+ years of experience with 7+ years of experience working as a senior mechanical design engineer or engineering team lead in a relevant context: design and implementation of R&D systems and manufacturing equipment

Ability to conceive of novel solutions for complex engineering systems in challenging environments

Expertise with 3D modeling; preferred experience with SolidWorks and NX

Experience with COMSOL, ANSYS or other FEA tools

Ability to select and qualify vendors for components or subsystems

Demonstrated ability to lead in either direct or matrix structures

Strong verbal and written communication skills and a dedication to high-quality documentation

Bonus points for:

Prior success building first-of-kind or experimental tools for material science or semiconductor R&D

Familiarity in applying Semi-S8, ASME, ACI, ASTM, and other mechanical standards to design solutions

Experience with the operation of equipment in a manufacturing environment

Must-have Requirements:

Ability to occasionally lift up to 50 lbs

Perform activities such as stooping, climbing, standing, or sitting for extended periods of time

Dedication to safety to mitigate industrial hazards that may include heat, cold, noise, fumes, strong magnets, lead (Pb), high voltage, and cryogenics

Willingness to travel or work required nights/weekends/on-call occasionally

#LI-Onsite
At CFS, we excel in fast-paced environments, driven by our values of integrity, execution, impact, and self-critique. As we grow, we’re eager to bring on mission-driven folks who offer diverse perspectives and fresh ways to tackle challenges. We value diversity deeply and are proud to be an equal opportunity employer by choice. We consider all qualified applicants equally, regardless of race, color, national origin, ancestry, citizenship status, protected veteran status, religion, physical or mental disability, marital status, sex, sexual orientation, gender identity or expression, age, or any other basis protected by law. This role requires compliance with U.S. laws concerning the export of controlled or protected technologies or information (collectively, “Export Control Laws"). Any offer of employment will be contingent on the need for compliance with such Export Control Laws.