Senior Manufacturing Engineer

About RadiantRadiant is an El Segundo, CA-based startup building the world’s first mass-produced, portable nuclear microreactors. Rising energy demand is straining the U.S. grid and driving up utility costs, emissions, and interconnection backlogs. Radiant decentralizes energy, producing power close to where it’s used. Its first reactor, Kaleidos, is a factory-built, 1-megawatt, fail-safe microreactor that can be transported by land, sea, or air and runs up to 5 years without refueling. Deployed locally without a decade-long build or permitting fight, Kaleidos provides independent power for critical infrastructure like military bases, data centers, hospitals, and remote sites. Founded in 2020, Radiant is under contract to deliver power to the U.S. Army, Air Force, Navy, and has pre-order agreements with Equinix, with deployments beginning in 2028.About the RoleRadiant is seeking a Senior Manufacturing Engineer to help transition Kaleidos from a first-of-a-kind reactor build into a repeatable, scalable production system.With the initial Kaleidos reactor build complete, Radiant is now applying what we learned through design, fabrication, assembly, integration, and test to the next generation of the product. This includes reducing mass and part count, improving manufacturability and assembly, increasing production repeatability, and developing the processes, tooling, equipment, suppliers, and quality controls required to manufacture reactors at scale.In this role, you will work closely with design, quality, test, supply chain, and operations engineers to influence hardware from the earliest stages of design through fabrication and final assembly. You will own manufacturing processes for critical reactor components, mechanisms, structures, and integrated assemblies, ensuring designs can be built safely, reliably, and repeatedly while meeting demanding performance and quality requirements.You will be expected to identify manufacturing constraints early, drive DFM and DFA into the product, develop and qualify production processes, and close the loop between engineering intent and what happens on the factory floor. The ideal candidate is equally comfortable reviewing a CAD model with a design engineer, developing a fixture or manufacturing process, troubleshooting a build issue, working with a supplier, and using production data to improve the next iteration of the product.This is a hands-on engineering role with significant influence over how Kaleidos evolves from a development program into a manufacturable product.Responsibilities & DutiesOwn manufacturing and inspection processes for critical Kaleidos components, mechanisms, structures, and assemblies from design release through fabrication, integration, and final acceptance.Partner closely with design engineers to drive design for manufacturability and assembly (DFM/DFA), influencing hardware to reduce mass, part count, manufacturing complexity, assembly time, and production risk.Evaluate designs for manufacturability, inspectability, tolerance stack-up, tooling access, assembly sequence, subsystem integration, and final reactor assembly.Develop, qualify, document, and continuously improve manufacturing processes for complex mechanical hardware and integrated assemblies.Translate engineering drawings, CAD models, requirements, and specifications into manufacturing plans, work instructions, inspection strategies, tooling requirements, and production controls.Define fabrication and assembly approaches for new hardware, including process selection, sequencing, make-versus-buy decisions, and inspection methodology.Design and develop production tooling, fixtures, assembly aids, lifting equipment, and other manufacturing equipment required to safely and repeatably build reactor hardware.Partner with Quality and Test Engineering to establish inspection and acceptance strategies, resolve build and test issues, and incorporate lessons learned into future hardware and processes.Investigate manufacturing defects, nonconformances, and assembly issues using structured root-cause analysis and implement durable corrective actions.Identify, evaluate, and develop suppliers for critical components and manufacturing processes, working directly with suppliers to mature fabrication methods and resolve technical issues.Identify and implement capital equipment, machinery, and production infrastructure needed to support current builds and future production volumes.Support hands-on build, integration, and troubleshooting activities while identifying opportunities to improve repeatability, throughput, yield, labor content, and production scalability.Required Qualifications & SkillsBachelor’s degree in mechanical engineering, manufacturing engineering, aerospace engineering, or a related technical discipline from an accredited institution.5+ years of experience manufacturing complex mechanical hardware in a production, development, or high-reliability engineering environment.Demonstrated experience partnering with design engineering to influence hardware through DFM/DFA.Experience owning manufacturing processes from development through qualification and production implementation.Strong understanding of mechanical fabrication and assembly processes, including machining, joining, fastening, alignment, tolerance control, and inspection.Strong ability to interpret engineering drawings, CAD models, specifications, and Geometric Dimensioning & Tolerancing (GD&T).Experience developing manufacturing documentation such as work instructions, process specifications, routings, and inspection plans.Experience troubleshooting manufacturing and assembly problems, performing root-cause analysis, and implementing corrective actions.Demonstrated ability to make practical engineering tradeoffs across manufacturability, quality, cost, schedule, performance, and risk.Experience working directly with technicians, machinists, fabricators, inspectors, and operators in a hands-on manufacturing environment.Strong written and verbal communication skills and the ability to work effectively across design, quality, test, supply chain, and operations teams.Preferred Qualifications & SkillsMaster’s degree in mechanical engineering, manufacturing engineering, or a related technical discipline.Experience transitioning complex hardware from prototype or development builds into repeatable or scaled production.Experience manufacturing highly engineered hardware in aerospace, energy, nuclear, automotive, defense, turbomachinery, or another high-reliability industry.Experience with precision machining, mechanical joining, dimensional inspection, and non-destructive evaluation methods.Experience with tolerance analysis and manufacturing or assembly strategies for tightly controlled interfaces.Experience designing custom fixtures, tooling, assembly equipment, or other production hardware.Experience with process qualification, first article inspection, statistical process control, or production quality systems.Experience developing suppliers for low-volume, high-complexity hardware.Experience with manufacturing automation, production equipment, or semi-automated assembly systems.Demonstrated ability to reduce part count, mass, assembly time, production complexity, or manufacturing cost without compromising product performance.Additional RequirementsMust be willing to support extended hours and weekends when necessary to meet critical program milestones.Must work 100% onsite at Radiant’s El Segundo headquarters.Benefits and PerksStock: 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 BenefitsRadiant 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 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.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.Compensation Range: $133.5K - $184.8KLocationEl Segundo, CAEmployment TypeFull timeLocation TypeOn-siteDepartmentEngineeringProduction & ManufacturingCompensation$133.5K – $184.8K • Offers Equity