Radiant
Nuclear Energy
PrincipalEmbeddedSoftwareEngineer
Neural analysis suggests this role is
optimal for Principal candidates.
“Principal Embedded Software Engineer at Radiant. Skills: Embedded software architecture, RTOS, Embedded C/C++, System-level design. Define embedded software architecture. Establish patterns and standards”
Industry & Context.
Make high-consequence technical decisions with incomplete information
Willing to work extended hours and weekends, Work 100% onsite, Compliance with U.S. export controls
What They're Looking For.
Must Have
Bachelor's degree in computer engineering, computer science, electrical engineering, or a related field, 8+ years of industry experience in embedded software, Significant ownership of system-level architecture decisions, Demonstrated experience driving architecture across complex, multi-subsystem embedded programs, Hands-on experience with an RTOS (Zephyr, NuttX, ThreadX, etc.), Low-level bring-up and porting, Deep proficiency in embedded C/C++, Track record of influencing technical direction beyond your immediate team, Communicator capable of driving consensus across engineering, program, and leadership stakeholders
Nice to Have
Experience with Zephyr RTOS at an architectural or maintainer level, Experience working with Simulink Autocode C++ export in a production context, Experience with CMake in large, multi-target embedded builds, Proficiency in reading and interpreting hardware schematics, Ability to debug at the hardware/software boundary, Experience in safety-critical or high-reliability domains (aerospace, defense, medical, nuclear, or industrial)
What You'll Do.
Define embedded software architecture
Establish patterns and standards
Lead design and development
Develop and bring up new drivers
Serve as senior technical voice
Drive decisions across subsystems
Own full engineering lifecycle
Establish testing frameworks
Mentor embedded engineers
How You'll Work.
Team & Collaboration
Partner with electrical, controls, and hardware engineering leadership; Align on cross-disciplinary interfaces; Drive consensus across engineering, program, and leadership stakeholders
Communication Scope
Communicator capable of driving consensus
Full Job Description
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 Principal Embedded Software Engineer to set the technical direction for embedded software across instrumentation and control (I&C) systems. You will define architecture, establish engineering standards, and personally drive the development of mission-critical, highly performant embedded systems that interface with sensors and actuators at the heart of a first-of-its-kind reactor design. The ideal candidate thrives in ambiguous early-stage environments, can make high-consequence technical decisions with incomplete information, and leaves a lasting organizational imprint through the systems and culture they build. You will have the opportunity to shape the embedded software foundation of the first commercialized portable nuclear microreactor, technology that will redefine how the world accesses clean, reliable power. RESPONSIBILITIES AND DUTIES - Define and own the embedded software architecture for I&C systems, establishing patterns and standards that scale across the full program lifecycle. - Lead design and development of reliable, fault-tolerant embedded software for production hardware ope
Applying for this Principal Embedded Software Engineer role?
Most applicants get filtered before a human reads their resume. See if yours makes the cut.
How to Apply on Ashby
- Ashby is a fast modern ATS — most applications take under 3 minutes.
- The resume parser is strong; verify parsed experience dates and job titles.
- Custom screening questions are often scored algorithmically — answer completely.
- Location field affects geo-based screening; use your actual metro area.
ANONYMOUS · UNFILTERED
What do employees actually say about Radiant?
Real rants from real employees. Read before you apply.