Subassemblies Specialist

Commonwealth Fusion Systems; Harvard (MA); On-site; USD 90,000 - 145,000; Full time

Benefits offered by this job

Competitive compensation with equity

Flexible vacation days

Health, dental, and vision insurance

401(k) with employer matching

Job summary

Commonwealth Fusion Systems is seeking a Subassemblies Specialist in Massachusetts. The role focuses on delivering precision subassemblies for the SPARC Tokamak, requiring meticulous attention to detail and strong technical assembly skills. Applicants should have 5–7 years in a technical assembly role, leadership experience, and the ability to operate machining tools. The position offers a competitive salary of $90,000 - $145,000 per year, along with equity and benefits such as health insurance and flexible vacation days.

Qualifications

• 5–7 years in a highly technical assembly role.
• 2 years leading a team of four or more workers.
• Ability to use basic machining tools.

Responsibilities

• Build complex and simple subassemblies and components.
• Oversee contract technicians to ensure quality.
• Perform testing with helium leak checking.

Skills

Technical assembly experience

Leadership skills

Forklift operation

Machining tools usage

Measurement tools proficiency

Project management

Self-motivation

Education

High school diploma or equivalent

Tools

JIRA

Manufacturo

Job description

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 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 Subassemblies Specialist

The Subassemblies team is responsible for delivering precision, ultra high vacuum subassemblies for seven major teams that go into the SPARC Tokamak. As a Subassemblies Specialist, you will be the last set of hands and eyes on critical parts; as such, meticulous attention to detail in build quality is necessary. You will draw upon your years of technical experience building complex systems to help streamline workflows and deliver the best possible parts. Once all the subassemblies are built (roughly a two year timeline) you will be uniquely qualified to install the subassemblies into the Tokamak and your role will transition to the Assembly of the machine. This role is truly a once in a lifetime opportunity to use hands‑on assembly skills to accelerate the development of fusion energy by ensuring SPARC is built on time and to high quality. The main systems you will be building are high power RF antennas, plasma facing components, port plugs, error field correction coils, vertical stability coils and plasma diagnostics; the bespoke tools used for real‑time control of a burning plasma and to achieve SPARC's science mission.

What you’ll do

• Build complex and simple subassemblies and components while maintaining all cleanliness specifications
• Oversee contract technicians; ensuring they are following work instructions and are delivering quality parts
• Perform testing and check-outs with helium leak checking and various other check‑out equipment
• Work together with scientists and engineers to refine work instructions
• Help to finalize design of components that interact with the tooling
• Assist with precision alignment and installation of active and passive optical systems
• Actively participate in maintaining mandatory cleanliness of work area and clean room
• Assist other CFS teams with related skilled work
• Participate in developing strategies to quickly overcome non‑conformances encountered in the field

What we’re looking for

• High school diploma or equivalent experience
• 5–7 years in a highly technical assembly role; e.g., aerospace/aircraft, racing, semiconductor, oil & gas, laboratory, wind, automotive
• 2 years leading a team of four people or more
• Can operate a forklift
• Experience creating designs for tooling
• Experience completing large scale projects end to end
• Ability to use basic machining tools; e.g., lathe/mill
• Experience using measurement tools
• Experience using JIRA, Manufacturo, or other software based tracking
• Experience rigging and lifting heavy components
• Highly self‑motivated, organized, and passionate about their work

Bonus points

• Welding experience
• Knowledge of clean room best practices
• Knowledge of cryogenic systems
• Knowledge of six sigma process

Essential Requirements

• Ability to occasionally lift up to 50 lbs
• Ability to perform activities such as sitting, climbing, stooping, typing, and standing for extended periods of time
• Willingness to occasionally travel for required nights/weekends/on-call
• Dedication to safety to mitigate industrial hazards that may include heat, cold, noise, fumes, strong magnets, lead (Pb), high voltage, 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

#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.