Software Engineering Manager - Simulation

Software Engineering Manager – Simulation

Radiant is an El Segundo, CA-based startup building the world’s first mass-produced, portable nuclear microreactors. The company’s first reactor, Kaleidos, is a 1-megawatt failsafe microreactor that can be transported anywhere power is needed and run for up to five years without refueling. Portable nuclear power with rapid deployment can replace similar-sized diesel generators and provide critical asset support for hospitals, data centers, remote sites, and military bases.

Radiant’s approach uses modern software engineering to rapidly achieve safe, factory-built microreactors that leverage existing, well-qualified materials. Founded in 2020, Radiant is on track to test its first reactor next year at the Idaho National Laboratory, with initial customer deliveries in 2028.

Radiant is seeking a Software Engineering Manager for Simulation to build and lead the engineering team responsible for reactor physics modeling, thermal-hydraulics simulations, and Digital Twin development. In this role you will scale a high-performing team while maintaining technical depth, ensuring our simulation infrastructure enables Radiant to design, test, and validate reactor systems—accelerating our path to commercialization.

• Build, lead, and mentor a team of simulation engineers developing thermal, hydraulic, and nuclear models for reactor and subsystem physics.
• Guide technical architecture and implementation for simulation systems.
• Scale software infrastructure to support Digital Twin simulation, visualization, and data processing capabilities.
• Define and own the technical roadmap for thermal and safety analysis simulation; develop and execute a strategy for model tuning as models evolve.
• Foster a culture of technical excellence by establishing best practices for simulation software development, code quality, and testing.
• Collaborate cross-functionally with Hardware, Nuclear, and Electrical engineering teams to accelerate software-in-the-loop and hardware-in-the-loop testing capabilities.
• Own team delivery of mission-critical internal simulation products while ensuring sustainable development practices and technical debt management.
• Recruit, develop, and retain top engineering talent and build a high-performance team culture.

• 7+ years of professional software engineering experience with significant depth in simulation, scientific computing, or physics-based modeling.
• 2+ years of people-management experience leading engineering teams.
• Strong technical background in programming languages such as Python, Rust, C#, or C/C++.
• Experience building and scaling highly technical engineering teams.
• Familiarity with simulation tools, physics-based modeling, numerical methods, or computational science sufficient to guide technical strategy.
• Familiarity with numerical solvers, visualization frameworks, and automated testing approaches for scientific software.
• Strong foundation in software engineering best practices, including version control, code review, and CI/CD pipelines.
• Proven ability to balance hands‑on technical contributions with team leadership and people development.
• Bachelor’s degree in physics, mechanical engineering, computer science, or a similar field, or equivalent experience.

• Advanced degree (Master’s or Ph.D.) in physics, mechanical engineering, computer science, or a similar field.
• Experience managing teams working on simulation or computational modeling, parallel computing, or high-performance computing.
• Background with modern simulation frameworks, finite-element analysis, or computational fluid dynamics tools.
• Track record of successful cross-functional collaboration with Hardware, Nuclear, and Electrical engineering teams.
• Strong communication and stakeholder-management skills with the ability to translate technical complexity for diverse audiences.
• Experience with Machine Learning, Deep Learning, AI, or other probabilistic modeling techniques.

• Must work 100% onsite at El Segundo HQ.
• Must be willing to work extended hours and weekends as necessary to accomplish our mission.