About Radiant

Radiant is an El Segundo CA-based startup building the worlds first mass-produced portable nuclear microreactors. The companys first reactor Kaleidos is a 1-megawatt fail-safe microreactor that can be transported anywhere power is needed and run for up to 5 years without refueling. Portable nuclear power with rapid-deploy capability can replace similar-sized diesel generators and provide critical asset support for hospitals data centers remote sites and military bases. Radiants unique practical approach to nuclear development leverages modern software engineering to rapidly deliver safe factory-built microreactors that use existing well-qualified materials. Founded in 2020 Radiant is on track to test its first reactor at the Idaho National Laboratory this summer with initial customer deliveries beginning in 2028.

About the role

Radiant is seeking a highly motivated and detail-oriented Control Systems Engineer to join our this role you will be responsible for designing implementing and validating nuclear reactors as well as developing maintaining executing and automating test cases across the full testing lifecycle for our reactor control systems. You will collaborate closely with systems engineers controls developers and software teams to ensure the highest quality and reliability in safety-critical control software. A strong foundation in model-based design software testing methodology and control systems theory is essential to succeeding in this role.

Responsibilities & Duties

• Develop control algorithms embedded software and analytic models to derive and flow down requirements to components and subsystems.

• Analyze and review control system Simulink models and design artifacts to understand system behavior control logic and closed-loop performance.

• Evaluate and validate auto-generated code via Simulink Coder or Embedded Coder ensuring traceability between model behavior and deployed software.

• Interpret reactor control system requirements to develop comprehensive test coverage across functional and non-functional requirements.

• Develop and maintain test artifacts including unit SiL HiL and hardware test cases.

• Execute test cases across the full testing spectrum: unit SiL HiL and hardware testing.

• Automate testing workflows for SiL HiL and hardware test cases using Python Go (Golang) or MATLAB.

• Design and implement Simulink Test harnesses including signal builder inputs baseline comparisons and coverage analysis.

• Apply software testing best practices equivalence partitioning boundary value analysis and requirements-based testing to control system verification.

• Run structured test campaigns including regression suites; document results with metrics pass/fail criteria and issues.

• Collaborate with controls developers and systems engineers on root cause analysis and defect resolution.

• Contribute to the continuous improvement of test processes frameworks and tools.

Required Qualifications & Skills

• Bachelors degree in Electrical Engineering Computer Engineering Mechanical Engineering Computer Science or a related discipline.

• 3 years of experience with Simulink/MATLAB including dynamic system models and model-based design workflows.

• 1 years of experience in controls engineering.

• Strong understanding of control systems fundamentals: closed-loop architectures feedback control and state-space or transfer function representations.

• 3 years of experience in unit integration SiL HiL and system testing.

• Proficiency in test automation scripting (e.g. Python Golang or similar).

• Hands-on experience with Simulink Test: test sequencing coverage measurement and baseline comparison workflows.

• Excellent analytical skills attention to detail and strong written and verbal communication.

Desired Qualifications & Skills

• Experience with safety-critical or regulated systems (e.g. aerospace automotive energy).

• Experience with Simulink Coder or Embedded Coder and validating generated code against model behavior.

• Familiarity with version control (e.g. Git) and CI/CD pipelines for model-based design.

• Prior exposure to automated test frameworks hardware interfaces and real-time data capture.

• Background in PID tuning gain scheduling or other control design techniques for embedded or real-time systems.

Additional Requirements

• Must be willing to work extended hours and weekends as necessary to accomplish our mission

• Must work 100% onsite at El Segundo HQ

Benefits and Perks

• Stock: Substantial incentive stock plan for all full-time employees.

• Medical: 100% up to base silver level plan for employee 50% dependents offers up to Platinum plans.

• One Medical: Sponsored memberships for employees and their dependents.

• Vision: 100% top tier plan coverage 50% for dependents.

• Dental: 100% top tier plan coverage orthodontia extra 50% for dependents.

• Voluntary life accident hospital critical illness commuter and FSA/HSA are offered as employee contributed benefits.

• 8-weeks of paid parental leave for all parents. Additional paid pregnancy leave for CA employees.

• Daily catered lunch. Free snacks and drinks.

• Flexible PTO policy. Remote workday allocation.

• Company and team-bonding events happy hours and in-person camaraderie.

• Beautiful El Segundo headquarters close to the Pacific Ocean.

Total Compensation and Benefits
Radiant compensates people for impact and invests in those who continue to raise the bar. Radiants new hire compensation package includes base salary substantial equity grants and comprehensive health benefits. Total compensation and level are determined through a rigorous evaluation of interview performance experience education and qualifications and are designed to support continued growth as scope responsibility and impact expand at Radiant.

The best of todays advanced reactor builders dont wait for job postings. They join the winning team. If thats you contact us directly for immediate opportunities: .

We are an equal opportunity employer and all qualified applicants will receive consideration for employment without regard to race color religion sex sexual orientation gender identity or expression pregnancy age national origin disability status genetic information protected veteran status or any other characteristic protected by law.

Unfortunately we are unable to provide visa sponsorship at this time.

This position involves access to technology that is subject to U.S. export controls. Any job offer made will be contingent upon the applicants capacity to serve in compliance with U.S. export controls.

Required Experience:

IC