Principal Embedded Software Engineer

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.

Responsibilities

• 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 operating in demanding environments.
• Develop and bring up new drivers for I&C hardware across a range of sensing and actuation subsystems.
• Serve as the senior technical voice in design reviews, setting the bar for rigor, surfacing systemic risks, and driving decisions that span multiple subsystems and teams.
• Own the full engineering lifecycle, from architecture through test, build, and field implementation, and set expectations for how the team executes that lifecycle.
• Establish robust hardware and software testing frameworks, validation methodology, and documentation standards that meet rigorous safety requirements.
• Mentor embedded engineers across the team; model technical excellence and engineering judgment.
• Partner with electrical, controls, and hardware engineering leadership to align on cross-disciplinary interfaces and constraints.

Requirements

• Bachelor's degree in computer engineering, computer science, electrical engineering, or a related field.
• 8+ years of industry experience in embedded software, including significant ownership of system-level architecture decisions.
• Demonstrated experience driving architecture across complex, multi-subsystem embedded programs, not just feature ownership.
• Hands-on experience with an RTOS (Zephyr, NuttX, ThreadX, etc.), including low-level bring-up and porting.
• Deep proficiency in embedded C/C++.
• Track record of influencing technical direction beyond your immediate team, through documentation, standards, or cross-functional alignment.
• Strong communicator capable of driving consensus across engineering, program, and leadership stakeholders.

Qualifications

• 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).

Benefits

• 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.
• A beautiful El Segundo headquarters close to the Pacific Ocean.

Pay

$200,500 – $314,475

Schedule

Full time, On-site