Mechanical Engineer - Toroidal Field Coil

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 working with policymakers and suppliers to build the energy industry of the future.

We’re in the best position to make it happen. Since 2018, we’ve raised nearly $3 billion in capital, making us the largest and leading private 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 Mechanical Engineer – Toroidal Field Coil

Commonwealth Fusion Systems (CFS) collaborates with MIT to leverage groundbreaking high-temperature superconducting (HTS) magnet technology to build compact fusion power plants. As a Mechanical Engineer on the SPARC Toroidal Field (TF) Coil System Winding Pack team, you will act as a "Core Player"—a reliable and versatile contributor executing on mid-to-long-term assignments that are critical to the project's success. You’ll also work closely with peers across the organization - from other HTS magnet systems, R&D, Physics, Quality, Production, Assembly, Program Management - to ensure success of the SPARC mission.

In this role, you will own technical execution of a key Winding Pack subassembly as it transitions from final design to physical reality. You will serve as the technical anchor on the manufacturing floor, using deep mechanical engineering fundamentals to resolve complex non-conformances and validate "as-built" conditions. This position offers a unique vantage point: by mastering the practical challenges of building and testing the SPARC TF coils today, you will build the deep, hands-on intuition required to design the high-field, superconducting magnet systems of the future. We are looking for a self-starter who values continuous learning and is eager to bridge the gap between rigorous analysis and rapid execution.

What you'll do:

- Use first principles physics as a basis for all decisions

- Act as the primary technical resource for "shipside" support, collaborating closely with quality and manufacturing to solve emerging challenges during production, assembly, and installation

- Perform structural and thermal calculations, ranging in complexity from first-principle hand calculations to FEA

- Solve integrated engineering challenges across multiple disciplines to proactively mitigate engineering and operational risks

- Generate detailed work plans and define milestones for the transition from component manufacturing to SPARC assembly

- Anticipate operational trends and challenges, contributing to future-oriented planning for SPARC commissioning

What we’re looking for:

- Bachelor’s degree in mechanical engineering, aerospace engineering, physics, robotics, or another relevant field

- Candidates with degrees in Electrical Engineering who have strong mechanical or structural engineering competency should feel encouraged to apply

- 3+ years' experience in design-build fundamentals: CAD (NX Preferred), component selection, structural analysis, design for manufacturing, GD&T

- Experience working in an extremely fast paced environment

- Experience taking a part from concept through production, with a proven ability to resolve technical hurdles in a manufacturing setting

- Demonstrated ability to perform structural analysis via hand calculations and FEA (ANSYS Workbench preferred)

- Familiarity with interpreting GD&T and inspection reports

- A deep understanding of mechanical and structural engineering fundamentals

- Familiarity with electromagnetic fundamentals – voltage, current, resistance, Ohm’s Law, AC/DC, right-hand rule, solenoids, etc

- Ability to innovate creative solutions to challenging problems

- A can-do attitude and an eagerness to learn

- Ability to operate with general guidance and take independent ownership of execution approaches.

- High self-motivation and drive to execute quickly

- Effective at communicating technical topics to both technical and non-technical audiences

- Alignment with CFS values of integrity, execution, impact, and self-critique

Bonus points for:

- Prior experience in liaison engineering, field service, or manufacturing support where you worked physically near hardware to resolve integration issues

- Experience with design and/or testing of complex electromechanical systems

- Experience designing components for high vacuum and/or cryogenic operating environments

- Experience in the development of technical specifications and procedures

- Familiarity with other magnet systems or complex large-scale hardware (e.g., solenoids, pressure vessels, cryogenic systems)

- Familiarity with fluid dynamics

- Familiarity with programming languages (MATLAB, Python, etc.) especially oriented toward data analysis, data manipulation and data acquisition and control

Must-have Requirements:

- Ability to occasionally lift up to 50 lbs

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

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

- Work in a facility that contains industrial hazards including heat, cold, noise, fumes, strong magnets, lead (Pb), high voltage, high current, pressure systems, and cryogenics

Salary range for this full-time position + equity + benefits. The actual salary will depend on level, location, qualifications, and experience. The range displayed on each job posting reflects new hire salaries for the position across all US locations. Benefits include:

- Competitive compensation with equity

- 12.5 Company-wide Holidays

- Flexible vacation days

- 10 sick days

- Generous parental leave policy

- Health, dental, and vision insurance

- 401(k) with employer matching

- Professional growth opportunities

- Team-building activities

#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.