Control Systems Engineer

About Radiant 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, 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.

Radiant's 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 team.

In 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 * Bachelor's 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.

Radiant's 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 today's advanced reactor builders don't wait for job postings.

They join the winning team.

If that's 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 applicant's capacity to serve in compliance with U.S.

export controls.