Senior Cost Accountant
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.
Contact
Last updated on 2026-01-02 | 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 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 Senior Cost Accountant
The Senior Cost Accountant will support key Accounting and Inventory controls across the organization while being a contributing member of the team handling standard cost management, variance analysis, and inventory valuations. This team member will work closely across multiple departments at CFS and must be a goal oriented team player who displays a strong intuition on how to tackle novel costing challenges.
What you'll do
- Standard Cost Management
- Develop, maintain, and update standard costs for raw materials, labor, and overhead
- Monitor and analyze cost variances, including material, labor, and overhead variances
- Review and adjust standard costs to reflect changes in manufacturing processes and market conditions
- Ensure we accurately capture and apply costs to projects across the company
- Cost Analysis & Reporting
- Analyze manufacturing costs and prepare detailed reports on cost performance
- Identify trends and variances in production costs and recommend corrective actions
- Provide detailed cost analysis and insights to support decision-making for pricing, budgeting, and forecasting
- Provide cost-related data and analysis to support financial planning
- Variance Analysis
- Conduct variance analysis on actual vs. standard costs, explaining reasons for differences
- Work with production and operations teams to understand and mitigate cost variances
- Prepare regular reports on cost variance, highlighting areas of concern and opportunities for cost reduction
- Prepare journal entries to allocate cost variances
- Inventory Management
- Assist in monitoring and valuing inventory, ensuring accuracy in cost allocation
- Conduct periodic inventory reconciliations and analyze inventory variances
- Support physical inventory counts and investigate discrepancies between physical counts and system records
- Continuous Improvement
- Collaborate with cross-functional teams to assess processes, their inputs, outputs, quality and other factors, in order identify and implement improvements to process quality, accuracy and cost
- Support the development and implementation of process improvements related to cost accounting and reporting, as well as other accounting processes, including purchase order accuracy and completeness, credit memo application, parent-child effectiveness, etc.
What we're looking for
- Bachelor's degree in accounting, finance or business administration preferred
- 7+ years' experience as a cost accountant, cost analyst, or similar role, with a focus on data analysis and knowledge of cost accounting principles and practices
- Experience with inventory in a manufacturing environment
- Ability to keep organized and demonstrate flexibility in a fast-paced environment
- Excellent analytical skills and strong attention to detail
- Strong Excel Skills
Bonus points for
- 2+ years audit experience with Big 4 or similar
Must-have Requirements
- Perform extended activities such as stooping, climbing, typing, standing, sitting, etc.
- 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
$110,000 - $185,000 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
- * 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
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.
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About the role
November 25, 2025
Full Time
Company
January 2, 2026
Hybrid
USD 110k–185k yearly
- Devens, Massachusetts, United States
7+ years
UTC-05:00
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