Intern - AI & Infrastructure Engineer - Spring 2027

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

Benefits offered by this job

Health insurance

Dental insurance

Vision insurance

401(k) matching

Professional growth opportunities

Team-building activities

Job summary

Commonwealth Fusion Systems seeks an AI & Infrastructure Engineering Intern to join our team on-site in Devens, MA. The 26-week program provides meaningful, hands-on work building AI tooling and internal applications while collaborating with multiple business teams.

You will gain experience with Python backend development, GitHub workflows, and LLM tooling, while learning to manage AI projects and maintain observability and security practices across the stack.

Qualifications

• Authorized to work in the United States
• On-site internship in Devens, MA
• 26-week program with full-time hours (40–50)
• Projects vary by team and year in school

Responsibilities

• Serve as first-line support for employees using AI tools
• Set up GitHub and AI tool access
• Develop and maintain internal AI applications
• Document current AI usage and coach peers toward self-sufficiency AI development

Skills

Python backend

GitHub workflows

LLM APIs

Docker

Linux basics

Security awareness

Communication

Tools

MCP server

RAG tooling

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 an AI & Infrastructure Engineering Intern

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

Program Details:

• 26 week internship
• 40-50 hours per week with set hourly salary based on year in school
• Opportunity 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:

• Serve as first-line support for employees using AI tools:
  • Help people build and version their own applications
  • Follow repo and file-management best practices
  • Get unstuck on the technical side of AI implementation
• Handle AI tooling onboarding:
  • Process license requests through the Service Catalog
  • Set up GitHub and AI tool access
  • Guide teams through creating and publishing marketplace plugins
• Develop and maintain internal AI applications:
  • Implement scoped features and write automated tests
  • Turn recurring user questions into training content and company documentation
• Meet with teams across the business to document current AI usage, identify aspirational use cases and bespoke problems, and coach interested individuals toward becoming self-sufficient AI developers

What we’re looking for:

• Python backend development
• Git/GitHub workflows: branching, pull requests, code review, etc.
• Experience building with AI coding tools, including configuring project rules, skills, or custom agents
• Working with LLM APIs: tool use, structured outputs, prompt and context management
• Building or deploying an MCP server
• Agent frameworks and observability or evaluation tooling
• RAG fundamentals: embeddings, vector stores
• Docker and Linux basics
• Authentication concepts: SSO, role-based access
• Strong communication - the intern will spend time meeting with non-technical teams
• Security and data-handling awareness - the role touches SSO, access provisioning, and internal data

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.