Intern - Scientific Software Engineer - Summer 2027

Commonwealth-Fusion-Systems-5; Harvard (MA); On-site; USD 34,000 - 52,000; Full time

Benefits offered by this job

Health insurance

Dental insurance

Vision insurance

401(k) with employer matching

Professional growth opportunities

Team-building activities

Job summary

Commonwealth Fusion Systems LLC in Devens, MA seeks a Scientific Software Engineering Intern to join a fast-paced, mission-driven team. You will port high-performance electromagnetics kernels to the GPU, extending cfsem with cross‑platform variants and Python bindings.

You will help ensure correctness through tests, benchmark performance against CPU kernels, and ultimately contribute merged open‑source work to a Rust/Python project for SPARC and future fusion magnets.

Qualifications

• Pursuing an engineering degree with focus in Computer Science.
• Contributed to a multi-person software project.
• Rust programming language proficiency.
• Software performance engineering experience (class, project or internship).
• Demonstrated initiative with strong troubleshooting skills.

Responsibilities

• Port high-performance electromagnetics kernels to the GPU.
• Ensure scientific correctness by validating against tests and CPU versions.
• Benchmark GPU performance and compare to CPU kernels.
• Ship open-source work by integrating with Python interfaces and contributing to Rust/Python projects.

Skills

Rust programming

Software performance engineering

Contributed to a multi-person software

Pursuing CS degree

Education

Engineering degree in Computer Science (in progress)

Tools

Rust

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, 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 Scientific Software Engineering Intern

We are looking for a talented Scientific Software Engineering Intern to join our team! CFS interns are highly valued within the organization and placed into meaningful and challenging roles.

Program Details:

• 13-18 week internship
• 40-50 hours per week with set hourly salary based on year in school
• Opportunities on site in Devens, MA. If an intern is going to be on site, you will be responsible for your own transportation and housing
• Specific project assignments and required technical skillset will vary based on the team’s existing need.
• Opportunities available for currently enrolled college students in all levels of schooling from bachelor’s degree to PhD
• Interns must be authorized to work in the United States for any employer

What you'll do:

• Port high-performance electromagnetics kernels to the GPU. You’ll start with the Biot‑Savart magnetic‑field calculation in cfsem, CFS’s open‑source Rust library, and extend it to include cross‑platform GPU kernel variants with Python bindings
• Hold your code to a scientific‑correctness bar. You’ll check the GPU kernels against cfsem’s existing unit tests and CPU versions, and determine if your methods are accurate enough for engineers who rely on the results to design superconducting magnets
• Measure and report GPU performance. You’ll benchmark speed and accuracy against the optimized multithreaded Rust CPU kernels, and present a clear recommendation on where GPU acceleration pays off and where it doesn’t
• Ship public open‑source work. You’ll put the new kernels behind cfsem’s existing Python interface so they reach CFS engineers working on SPARC and future fusion magnets, and you’ll leave with merged contributions to a public Rust/Python project

What we’re looking for:

• Pursuing an engineering degree with focus in the field of Computer Science
• Contributed to a multi‑person software project
• Rust programming language
• Software performance engineering (class, project or internship experience)
• Demonstration of exceptional results through a range of different pursuits
• High self‑motivation and drive to execute quickly with excellent troubleshooting/problem‑solving skills

Must-have Requirements:

• Willingness to travel or work required nights/weekends/on‑call occasionally
• Perform activities such as typing, 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

$25 - $38 an hour

Rates are aligned to your current year in school, ensuring equitable and consistent pay across our intern program.

For BS interns, the hourly rate is $25–$32

For MS/PhD interns, the rate is $35–$38

Benefits included for full‑time interns:

• 40 hours of sick time
• Health, dental, and vision insurance
• 401(k) with employer matching (must be 21 years of age to enroll)
• 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.