Hardware-in-the-Loop (HIL) 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 Hardware-in-the-Loop (HIL) Engineer to support the development and maintenance of Radiant’s NI PXI-based HIL system for Kaleidos. You will work closely with senior engineers to assist in hardware integration, testing, and validation of critical systems. This role is ideal for someone with foundational experience in HIL systems and a desire to grow their skills in real-time testing, automated validation, and electrical integration within a collaborative team environment. You will have the opportunity to contribute to the development of electrical integration systems that support the first high-temperature gas-cooled portable microreactor ever commercialized. Responsibilities and Duties: Assist in designing, building, and maintaining HIL test bench systems. Help configure test hardware, including power supplies, actuators, and sensor mapping. Support communication and integration with Digital Twin systems. Assist senior engineers with assembling and debugging HIL hardware and harnesses. Execute test procedures, collect data, and support analysis. Document test results, procedures, and lessons learned. Troubleshoot electrical and hardware issues with guidance from senior team members. Participate in design reviews and contribute ideas in a collaborative environment. Required Skills and Qualifications: BS in Electrical Engineering, Computer Engineering, or a related field. 2+ years of experience with HIL systems such as dSpace, NI PXI, Speedgoat, or similar platforms. Familiarity with NI HIL software (e.g., LabVIEW, TestStand) and programming/scripting in Python, C++, or C#. Hands-on experience with data acquisition, test execution, or electrical integration. Basic troubleshooting and debugging skills. Ability to work effectively in a team and communicate across disciplines. Desired Skills and Qualifications: Exposure to HW-SW integration and test procedures. Understanding of fundamental controls, software testing, and test processes. Interest in learning real-time simulation systems and FPGA-based systems. Familiarity with trace capture tools or data acquisition/analysis tools. 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: View email address on click.appcast.io. 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.