Commonwealth Fusion Systems

R&D Engineer

Join Commonwealth Fusion Systems in Devens, Massachusetts as an R&D Engineer. Lead testing and development of next-gen fusion HTS magnets, collaborating across disciplines. Enjoy competitive pay, equity, flexible vacation, and health benefits while advancing fusion energy technology.
Commonwealth Fusion Systems
Commonwealth Fusion Systems
Devens, Massachusetts, United States Hybrid Full time USD 90k–145k yearly UTC-05:00

Commonwealth Fusion Systems

Company Overview

Commonwealth Fusion Systems (CFS)

Cambridge, MA, United States

2018

Approximately 430 employees (source: zoominfo.com). Revenue figures vary, with reports indicating $211.3 million or $31.7 million, though as a pre-revenue fusion developer focused on R&D, these may reflect funding or operations rather than sales.

What They Do

Commonwealth Fusion Systems (CFS) is a pioneering private fusion energy company that specializes in tokamak-based magnetic confinement fusion. Founded as a spinout from MIT's Plasma Science and Fusion Center, CFS focuses on utilizing high-temperature superconducting magnets to achieve commercial net energy production (source: cfs.energy). The company has made significant strides in its technology, particularly with the development of compact fusion machines that leverage decades of tokamak science. Their flagship projects, SPARC and ARC, aim to demonstrate net energy gain and commercial viability in the coming years (source: cfs.energy).

Projects & Track Record

CFS is currently engaged in several groundbreaking projects, most notably the construction of SPARC, which is set to be the world's first net-energy fusion machine. Located at their Fusion Energy Campus in Devens, Massachusetts, SPARC aims to demonstrate net energy gain by the late 2020s (source: cfs.energy). Additionally, CFS is planning the ARC project, a 400 MW-class grid-scale tokamak power plant designed for commercial deployment in the early 2030s. These projects are underpinned by significant technological advancements, including the successful testing of the central solenoid magnet module (CSMC) in November 2024, which confirmed the manufacturability of critical components for SPARC (source: zoominfo.com).

Recent Developments

In the past two years, CFS has made remarkable progress, including the opening of its Devens Fusion Energy Campus on February 10, 2023, which was attended by notable figures such as U.S. Secretary of Energy Jennifer Granholm (source: cfs.energy). The company has also secured substantial funding, raising $863 million in August 2024, building on a previous $1.8 billion round in May 2023, bringing total funding to over $2 billion (source: wbjournal.com). Furthermore, CFS announced its first commercial power plant site in Chesterfield County, Virginia, which will be independently financed and operated, with plans for grid connection in the early 2030s (source: zoominfo.com).

Working There

CFS offers a range of roles across various disciplines, including fusion science, engineering, manufacturing, and materials science. The majority of their workforce is based at the Devens campus, which has grown to over 430 employees (source: cfs.energy). The company culture emphasizes rapid execution and transparency, attracting top talent from the fusion and manufacturing sectors. Key executives include Co-Founder and CEO Bob Mumgaard, along with other leaders in operations and science, indicating a strong demand for expertise in tough tech and physics (source: nasdaqprivatemarket.com). While specific benefits are not detailed, the scale-up and investor backing suggest competitive packages for high-caliber roles in a mission-driven environment (source: cfs.energy). Job seekers are encouraged to monitor their careers page for openings related to SPARC and ARC advancements.


Last updated on Feb 23, 2026 | Report an issue

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 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 R&D Engineer

The NINT Magnet R&D team is responsible for testing and retiring risks for CFS's NINT (non-insulated-non-twisted) HTS magnets. This includes executing development test campaigns for CFS's next-generation NINT magnet technology, and leading RCCA efforts through analysis and testing to resolve issues that may arise with the SPARC NINT magnets currently in production, tokamak integration, and commissioning. HTS magnet technology is inherently multidisciplinary, and a successful R&D engineer will seamlessly flex between disciplines and groups to effectively execute tests and projects on aggressive schedules supporting CFS's mission. The R&D engineer must have a fundamental understanding of mechanical, electrical, materials, fluids, and systems engineering, or some combination thereof. It is also the role of the R&D engineer to constantly push and challenge the requirements, risks, and test objectives that they are given to help the combined stakeholders come to a consensus on why the planned test is required and what data is deemed essential for the outcome to be achieved.

What you'll do

  • Develop new HTS magnet designs and their associated subsystems, which includes the designing and building R&D test samples, and developing their manufacturing processes and test operations
  • Design, build, and commission test equipment required to accomplish R&D test campaign objectives
  • Perform structural, electrical, and/or thermal analyses in support of R&D sample design and to predict test results
  • Build expertise in testing HTS magnets as well as how to design and build R&D HTS magnets and their associated subsystems, including power delivery, cryogenic cooling, and structures
  • Support the production, integration, and commissioning of SPARC NINT coils as issues requiring HTS magnet build and test expertise arise
  • Understand, challenge, and maintain well documented requirements and risks for the system or component under test, and align stakeholders on why the planned test is required and what data is deemed essential for the desired outcome to be achieved
  • Collaborate with I&C engineers to develop necessary instrumentation and data acquisition systems
  • Maintain documentation, schedules, and budgets for test campaigns. Documentation includes: design reviews, wiring lists, P&IDs, schematics, CAD assemblies, drawings, BOMs, data acquisition systems, and operations software
  • Develop custom tools to analyze generated data. Compile test results in presentations for review
  • Prepare and deliver presentations containing trade studies, design reviews, test readiness reviews, and test data reviews to teams of engineers and physicists

What we're looking for

  • Bachelor's degree in engineering or science field is required; mechanical engineering, electrical engineering or similar, or applied physics degree preferred
  • 3+ years' experience as an R&D engineer or test engineer designing, building, commissioning complex electromechanical systems
  • Experience with selecting and utilizing instrumentation and control components such as thermocouples, voltage and current sensors, oscilloscopes, pressure transducers, strain gauges, heaters, flow meters, fittings and valves
  • Experience with developing and executing test procedures
  • Proficiency with CAD design in Siemens NX or equivalent CAD software
  • Familiarity with electromagnetic fundamentals - voltage, current, resistance, Ohm's law, AC/DC, right-hand rule, solenoids, etc
  • Excellent troubleshooting / problem-solving skills with great attention to detail
  • Experience developing and effectively presenting comprehensive trade studies comparing the pros & cons of various technical approaches
  • Data reduction and analysis skills that can be used in generating anticipated results and processing generated data
  • Effective at communicating technical topics to both technical and non-technical audiences
  • High self-motivation and drive to execute quickly
  • Collaboration skills including active listening and facilitating production discourse on problems
  • Willingness to challenge the status quo in search of better, more efficient methods

Bonus points for

  • Experience with modeling/analysis software, especially ANSYS, COMSOL, and PLECS
  • Experience writing Python or MATLAB data tools for processing and analyzing data
  • Experience with high voltage and high current power equipment design and use - power supplies, water-cooled cables, insulation
  • Experience debugging electronics hardware and test software
  • Experience with designing and commissioning new test facilities
  • Experience designing fluid systems - P&IDs, component selection, ASME design codes
  • Experience with cryogenic equipment design for use with liquid nitrogen and supercritical helium - vacuum jacketed equipment, cryocoolers, phase separators, cold traps
  • Experience with high vacuum equipment design and use - roughing pumps, turbopumps, ion gauges, residual gas analyzers
  • Experience developing or improving manufacturing processes and handing off processes to production teams

Must-have requirements

  • Ability to occasionally lift up to 50 lbs
  • Perform activities such as typing, climbing, standing, stooping or sitting for extended periods of time
  • Willingness to occasionally travel or work required nights/weekends/on-call
  • 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

$90,000 - $145,000 a year

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
  • 13 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

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.

Apply now

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About the role

June 19, 2026

Full time

Company

June 19, 2026

Hybrid

USD 90k–145k yearly

Hydrogen

Commonwealth Fusion Systems

cfs.energy

  •  Devens, Massachusetts, United States

3+ years

UTC-05:00