Principal FPGA Engineer

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 next year, with initial customer deliveries beginning in 2028.

Radiant is seeking a Principal FPGA Engineer to serve as the technical authority for FPGA development across our Embedded Systems team. You will define the architecture, methodology, and standards governing FPGA design for a safety-critical instrumentation and control system responsible for real-time reactor control, sensor and actuator handling, and communications. This role operates at the intersection of deep technical ownership and organizational influence, shaping how Radiant approaches FPGA development as we bring the first commercial microreactor to market.

Responsibilities and Duties:

• Define and own the overall FPGA architecture strategy across Radiant's instrumentation and control systems, ensuring designs scale with evolving product and regulatory requirements.

• Establish org wide FPGA development standards, toolchain selections, and verification methodologies.

• Drive the most complex technical challenges, timing closure at scale, fault-tolerant design, multi-domain clock architectures, and set the precedent for how they are solved.

• Serve as the primary technical interface across Embedded Systems, hardware, software, and systems engineering, ensuring cohesive system-level design decisions.

• Lead architecture and design reviews, setting the quality bar for RTL, simulation, synthesis, and validation deliverables.

• Partner with engineering leadership to define hiring criteria and inform technical roadmap decisions.

• Mentor senior and mid level FPGA engineers, building long term technical depth across the organization.

Required Skills and Qualifications:

• Bachelor's degree in computer engineering, electrical engineering, or related field; advanced degree preferred.

• 10+ years of progressive FPGA development experience with demonstrated impact at a principal or staff engineer level.

• Expert level proficiency in VHDL, SystemVerilog, or equivalent HDL, with a track record of setting team-wide design standards.

• Mastery of full-cycle FPGA development, RTL architecture, simulation, synthesis, timing closure, and hardware bring up, across multiple platform generations.

• Deep experience with multi clock domain design, fault tolerant architectures, and safety critical systems.

Desired Skills and Qualifications:

• Experience in regulated development environments, including aerospace, defense, and manufacturing.

• Experience with the Microchip PolarFire SoC platform or comparable ecosystems.

• Proficiency with embedded C/C++ in FPGA/SoC contexts.

• Experience with formal or coverage driven verification methodologies at scale.

• Familiarity with CI/CD pipelines applied to HDL workflows.

• 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: [email protected].
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.