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 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 Senior Multiphysics Modeler The Senior Multiphysics Modeler will work closely with the CFS tritium program and process engineering team to develop a fuel cycle model for the world's first fusion power plant, ARC, located in Chesterfield County, Virginia. The senior multiphysics modeler will develop simulation toolkits and workflows that integrate first-principles multiphysics simulations with industrial process models to support technology development and subsystem integration for key fuel cycle systems, supported by the CFS fuel team to understand system requirements. The ideal candidate is an expert in heat and mass transport modeling, with an appreciation for simplicity and drive to build. This individual knows the power of optimizing devices by tuning material parameters, and appreciates a simple non-dimensional analysis and rigorous integrated simulations as the problem space requires. The candidate enjoys teaching and building tools that others can use independently. Applicants must have a degree in a relevant engineering or science discipline as well as experience in process modeling and programming. Applicants must have a demonstrated ability to apply a first principles approach in solving complex engineering problems and experience conducting cost-benefit to evaluate the economics of proposed solutions. Applicants must have demonstrated success working on engineering projects in multi-disciplinary teams generating effective solutions to complex problems.