Software Engineer - Digital Twin

Focused Energy is a fusion energy startup with the goal of generating unlimited clean energy to responsibly meet future global demand. With the use and commercialization of laser-induced inertial fusion, a clean and highly efficient power generation technology is coming within reach, suitable to ensure a secure and scalable future energy supply.

We are seeking a highly skilled and motivated software engineer to join our Science and Engineering team. In this role, you will help architect and scale Focused Energy’s digital twin platform—turning advanced physics and simulation models into a reliable, high-performance software system used across the company. You’ll play a key role in professionalizing our simulation codebase, defining software standards, and enabling fast, scalable collaboration between scientists, engineers, and systems teams.

• Build architecture for the digital twin platform, balancing performance, scalability, usability, and scientific rigor.

• Design, develop, and maintain high-performance systems code for fusion reactor studies, with an emphasis on modularity, reuse, and long-term maintainability.

• Establish and enforce testing, validation, and verification standards to ensure reliability, reproducibility, and trust in simulation results to ensure reliability and robustness

• Optimize code for performance and scalability

• Professionalize research and prototype code into production-quality software used across teams

• Design APIs and interfaces that enable fast iteration and clear communication between simulation, ML, and experimental systems

• Improve simulation throughput and turnaround time through performance optimization, parallelization, and scalable infrastructure

• Influence how software is built across the company by setting patterns, tooling, and engineering standards

• Contribute to the development of a comprehensive software ecosystem for fusion reactor studies

• Work closely with experimentalists and technical departments to validate and refine computational models.

• Collaborate with other research institutions and industry partners on joint projects

• Monitor technological advances in systems code and fusion reactor studies

• Comfortable operating in ambiguous, early-stage environments and making architectural tradeoffs with incomplete information

• Strong background in software development, engineering and/or computer science, preferably with a strong focus on modeling and simulation

• Familiar with the development and management of scalable cloud infrastructure, ideally as used in science, ML or other data processing-heavy use cases

• Strong foundation in statistics, computer science and machine learning

• Experience building maintainable and testable code bases, including API design and unit testing techniques

• Experience with HPC environments and developing scalable simulation workflows

• Proficiency in various languages e.g. Python, Fortran, MATLAB, C++

• Ability to articulate complex technical concepts clearly to multidisciplinary teams

• Experience with multi-physics simulations, physics-informed ML, or tightly coupled simulation–ML systems

• Background in fusion energy, plasma physics, or adjacent scientific computing domains

• Familiarity with systems engineering concepts, including verification, validation, and model lifecycle management

• Experience building internal platforms or tools used by other engineers or scientists at scale

• Contributions to shared research software, open-source projects, or collaborative academic/industry codebases

• Experienced in end-to-end/full-stack system design, ideally within an environment supporting physics, engineering or AI teams

• Experience with developing machine learning models at scale from inception to business impact

• Innovative Technology & Mission: Be part of a cutting-edge company working on groundbreaking research in clean energy and scientific discovery.

• Career Development: We invest in our people. This is an opportunity to join an early, growing company at the forefront of new technology, where you’ll have the opportunity to develop and grow your career.

• Collaborative Culture: Work with great people in a dynamic, international environment with top-tier scientists, engineers and professionals passionate about solving global challenges.

• Ownership: Take ownership from day 1 and drive impact by making decisions, solving challenges and shaping the future of our company.

• Your Success is our Success: We offer a competitive salary and company ownership in the form of stock options, giving you a direct stake in our success and ownership in what we build together.

• Flexibility: We believe work should adapt to your life—not the other way around. That’s why we offer a hybrid setup, giving you the freedom to work from our office while also enjoying the flexibility to work from home when it suits you.

• Events: We organize regular events to foster team bonding, encourage collaboration, and build a strong, supportive company culture. Connect with colleagues across departments, share ideas, and have fun together, both in and outside of the workplace.

Focused Energy is an equal opportunity employer committed to creating an inclusive environment. Qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender perception or identity, national origin, age, marital status, protected veteran status, or disability status.

Pursuant to the San Francisco Fair Chance Ordinance, Focused Energy will consider for employment qualified applicants with arrest and conviction records.

Compensation offered will be determined by factors such as location, level, job-related knowledge, skills, and experience. Certain roles may be eligible for incentive compensation, equity, benefits.