Senior Algorithms and Simulation Software Engineer

Commonwealth Fusion Systems; Harvard (MA); On-site; USD 140,000 - 210,000; Full time

Benefits offered by this job

Equity

Health insurance

401(k) with employer matching

Generous vacation policy

Parental leave

Job summary

Commonwealth Fusion Systems is hiring a Senior Algorithms and Simulation Software Engineer to design and implement state estimation and control algorithms for real-time applications in the SPARC project. You will build simulation frameworks, software testbeds, and production-quality code likely to run on mission-critical hardware.

You will collaborate across engineering teams, write robust Python and real-time languages (C++/Rust), and contribute to tooling, data analysis, and validation of

Qualifications

• Bachelor’s degree in engineering or related field.
• 7+ years of relevant experience.
• Experience writing real-time state estimation and control algorithms.
• Experience writing production-grade state estimation and software.
• Familiarity with modern software development lifecycle practices (CI/CD, Git, unit tests).
• Proficiency with Python and at least one real-time language such as C++ or Rust.

Responsibilities

• Develop state estimation and control algorithms for mission-critical applications.
• Build software infrastructure for HITL and software-only testbeds.
• Create simulation models and high-fidelity simulations.
• Develop offline data analysis tools.
• Collaborate with hardware and software teams to integrate solutions.

Skills

Python

C++

Rust

Real-time control

Education

Bachelor’s degree in engineering

Tools

Git

CI/CD

Job description

About Commonwealth Fusion Systems:

Commonwealth Fusion Systems is on a mission to deliver the urgent transition to fusion energy.

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 Senior Algorithms and Simulation Software Engineer

In this role you will be responsible for the design and implementation of state estimation and control algorithms, plus models and simulation framework necessary to verify those algorithms. Your algorithms will be used in critical real‑time applications in the SPARC project, as well as related projects.

As a member of the Software Engineering team, you will be a hands‑on technical contributor. You will be a champion of writing excellent quality, production‑ready code for mission‑critical real‑time systems. You will collect functional requirements from customers and produce software solutions to meet these requirements.

You will work with a variety of engineers to integrate your software into software testbeds, hardware testbeds, and the production tools. You will also contribute to the broader software ecosystem to improve tooling and processes used across the company.

What you’ll do:

• Develop mission‑critical state estimation and control algorithms
• Develop software infrastructure to operate Hardware‑in‑the‑Loop (HITL) and software‑only testbeds
• Develop simulation models and model infrastructure for both real‑time and off‑line (high fidelity) simulations
• Develop offline data analysis tools
• Help define and execute end‑to‑end and other integrated test cases and test plans to validate SPARC control software

What we’re looking for:

• Bachelor's degree in a relevant engineering field (computer science, computer engineering, electrical engineering, industrial engineering, etc.)
• 7+ years relevant experience
• Professional experience writing real‑time state estimation and control algorithms
• Professional experience writing production quality state estimation and software
• Experience with modern software development lifecycle practices (CI/CD, git version control, unit testing, integration testing, etc)
• Proficiency with python
• Proficiency with at least one real‑time control language (c++, rust, etc)

Bonus points for:

• Experience with Hardware‑in‑the‑Loop testbeds and software‑only testbeds for validating control software
• Experience writing models to validate software
• Familiarity with Linux
• Familiarity with general networking (IP/UDP)

Must-have Requirements:

• Perform activities such as typing, standing, sitting, etc. 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, high current, pressure systems, and cryogenics
• Willingness to occasionally travel or work required nights/weekends/on-call

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.

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