Principal Electrical Engineer, Integration & Test

Principal Electrical EngineerRadiant is 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.Founded in 2020 and based in El Segundo, CA, Radiant is on track to test its first reactor at the Idaho National Laboratory, with initial customer deliveries beginning in 2028. The approach leverages modern software engineering to rapidly deliver safe, factory-built microreactors using existing, well-qualified materials.Radiant is looking for a Principal Electrical Engineer to lead the electrical system architecture and test infrastructure for Kaleidos, Radiant's commercial microreactor targeted for deployment in 2028. You will own end-to-end electrical integration — from early architecture and requirements definition through hardware bring-up, testing, and commissioning — and serve as the technical authority ensuring the electrical and validation systems are ready to support that milestone.This is a high-autonomy, high-ownership role. You will make architecture decisions independently, set technical direction, mentor engineers, and collaborate across mechanical, software, and systems engineering teams to drive a complex program forward under tight timelines.What You'll DoDefine and own electrical and software integration requirements spanning power distribution, signal conditioning, sensor mapping, actuator interfaces, and device simulationOwn and build out the electrical test infrastructure for Kaleidos, establishing the test environment as a foundational asset to validate the commercial unit ahead of the 2028 deployment targetEstablish and maintain communication between hardware, control systems, and software interfacesDefine and drive electrical validation strategy; develop test procedures, methodologies, and best practicesManage schedule, budget, and vendor relationships for electrical hardware and integration activitiesOptimize test and validation processes; develop tooling and automation to improve efficiencySupport electrical integration across multiple critical systems and subsystemsLead design reviews and communicate technical decisions to cross-functional stakeholders across electrical integration, embedded, software, and controls teamsYou Should Have10+ years of progressive electrical engineering experience including hands-on hardware design, integration, and testDemonstrated experience setting technical direction, mentoring engineers, and driving programs with significant scope and ambiguityExperience with DAQ and test systems such as NI PXI, dSpace, Speedgoat, or similar platformsProficiency with LabVIEW, TestStand, and data acquisition systems, test execution, and validation frameworksProficiency in at least one scripting or programming language such as Python, C++, or C#Strong electrical and software debugging and root cause analysis skillsExperience working cross-functionally with software, mechanical, and systems engineering teamsBS in Electrical Engineering or a related disciplineWillingness to work extended hours and weekends as required; role is 100% on-site in El SegundoNice to HaveMS or PhD in Electrical Engineering or a related disciplineFamiliarity with real-time simulation systems or FPGA-based hardwareExperience with controls fundamentals and software testing processesHands-on experience with trace capture, data acquisition, and analysis toolsBackground in high-reliability, safety-critical, or regulated industries — aerospace, defense, nuclear, medical, or automotiveCompensation and BenefitsBase Salary: $200,500 - $314,475, plus substantial equity grants.Benefits include 100% employer-covered medical up to silver plan (50% for dependents) with Platinum plan options; 100% dental and vision coverage (50% for dependents); sponsored One Medical memberships for employees and dependents; FSA/HSA, commuter, and voluntary benefits; 8 weeks of paid parental leave for all parents; daily catered lunch and free snacks; flexible PTO; and remote workday allocation.