Senior Engineering Technician in Welding & Fabrication

Radiant Industries is hiring a Senior Engineering Technician specializing in Welding & Fabrication at its El Segundo, CA site. This technician partners with the Lead Welding Engineer and plays a central role in advancing nuclear reactor technology. The position blends hands-on welding and fabrication with a strong focus on quality assurance and production support. Main responsibilities Develop, implement, and maintain Welding Procedure Specifications (WPS), Procedure Qualification Records (PQRs), and Welder Performance Qualifications (WPQs) for both structural and pressure vessel welds. Interpret engineering drawings, CAD models, and technical specifications to plan and carry out welding and fabrication tasks. Collaborate with production and engineering teams to organize welding and fabrication operations from raw materials through final assembly. Design, build, and refine weld tooling, fixtures, and prototype assemblies to support manufacturing and product development. Deliver hands-on welding training to technicians, ensuring techniques and standards meet requirements. Perform precision fabrication, including cutting, forming, fit-up, and assembly of components and subassemblies. Lead welding and fabrication projects, ensuring all processes and inspections meet regulatory standards. Audit welding processes performed by suppliers to confirm quality and compliance. Identify and procure new equipment to expand in-house welding capabilities. Oversee procurement of consumables, tooling, and materials for welding operations. Support rapid prototyping and iterative development, working with engineering to improve designs for manufacturability. Work environment This position operates within a collaborative startup culture that values adaptability and practical problem-solving. The Senior Engineering Technician in Welding & Fabrication will influence both daily operations and long-term product development at Radiant Industries.

Senior Engineering TechnicianJoin Radiant Industries as a Senior Engineering Technician and leverage your diverse skill set in the fabrication and assembly of our cutting-edge microreactor unit. As a vital member of our team, you will play a key role in developing both large and small-scale test rigs, crafting prototype parts and tooling, and managing material handling. With significant autonomy, you will help establish and maintain our prototype shop at our new headquarters in El Segundo, California, utilizing your expertise in machining, welding, metal forming, electrical work, and plumbing. Your contributions will be instrumental in achieving the successful fueling of a groundbreaking reactor design by 2026.

Long Wall Company, established in 2025, is dedicated to advancing missile defense technology for the United States and its allied nations. By leveraging the RS1 and GS0 launch systems, our team is focused on creating containerized, mass-producible missile defense solutions that enable swift and cost-effective flight testing. We believe that enhancing global security and stability necessitates the development of defense technologies that are more affordable, better performing, thoroughly tested, and widely accessible than ever before. We invite you to be a part of this mission.Who We SeekMission-Driven Innovators. We are searching for engineers who approach aerospace challenges with creativity and tenacity. Ideal candidates are those who view setbacks as opportunities for growth and remain committed to delivering optimal solutions for our missions.Accountable Contributors. We value engineers who take full ownership of their work, understanding that collaboration is key to success. The most effective engineers elevate their teammates, as diverse skills create a multiplier effect that drives mission accomplishments.Role OverviewWe are in search of a seasoned avionics technician (S4 or S5) who is passionate about the development and manufacturing of hardware for launch vehicles and defense systems. The ideal candidate will be able to critically analyze and enhance hardware designs and production processes, ensuring that we deliver high-quality components to our projects. Responsibilities include building and testing electrical assemblies and components for our launch vehicles and defense systems, engaging in tasks such as PCB assembly and rework, electro-mechanical assembly, sensor/transducer integration, cable and wire harnessing, final integration, operation of thermal chambers, conducting functional tests, and executing software-driven testing.

Join Radiant Industries as a Senior Electrical Technician!In this pivotal role, you will leverage your expertise to support our engineering team in the development and assembly of cutting-edge electronic systems. Your contributions will ensure the reliability and functionality of our products, making a significant impact in the aerospace and military sectors.Responsibilities:Interpret and work with engineering drawings, electrical schematics, and wiring diagrams.Assemble, wire, and integrate hardware components such as PCBs, harnesses, electrical panels, and enclosures.Adhere to established procedures and specifications throughout the manufacturing process.Collaborate closely with engineers to enhance and document processes.Utilize manufacturing tools including soldering irons, cutters, strippers, crimpers, and torque wrenches with expertise.Conduct electromechanical tests such as continuity, hi-pot, and pull tests.Maintain a high standard of safety, cleanliness, and reliability in all operations.Demonstrate a solid understanding of electrical hardware and safe interaction practices.Required Skills:Experience with military or aerospace-grade electronics.Familiarity with high-power electronics and batteries.Understanding of production equipment and tooling for electromechanical manufacturing.Flexibility to support various projects aligned with company goals.Knowledge of NASA-STD-8739.4, IPC-A-610, IPC-A-620 standards.Experience with UL-508A and NFPA-70 (NEC) regulations.Preferred Qualifications:Ability to stand, bend, and work with small components for extended periods.Excellent vision and fine motor skills for precision work.Capability to lift up to 50 lbs occasionally.Strong teamwork, communication, and organizational skills.Positive attitude and ability to work effectively with minimal supervision.Strong organizational skills and attention to detail.Willingness to work outdoors when required.Ability to work at heights using scissor lifts or ladders as needed.Willingness to travel occasionally for offsite support.

Senior Manufacturing EngineerJoin Radiant Industries as a Senior Manufacturing Engineer, where you will collaborate with design engineers to revolutionize the production of intricate mechanisms and structures essential to our innovative microreactor technology. Your role will be critical in ensuring the reliability, safety, quality, and timely delivery of the Kaleidos demonstration unit, set for testing at the Idaho National Lab in 2026—marking the first new reactor design in over 50 years.Key Responsibilities:Oversee the manufacturing and inspection processes of vital components and assemblies within the Kaleidos microreactor.Collaborate with design engineers to create innovative production methods for complex mechanisms and structures.Develop, validate, and optimize manufacturing processes to fulfill all design and business requirements, including safety, quality, efficiency, and delivery timelines.Formulate and implement manufacturing specifications and fabrication instructions.Manage the manufacturing bill of materials (mBOM) for components and assemblies.Identify, evaluate, and establish partnerships with suppliers for component sourcing and fabrication.Identify, plan, and execute upgrades to capital equipment, machinery, and layout to adapt to evolving production needs.Lead initiatives that promote continuous improvements in manufacturing processes and product quality.

Join VardaSpace as a Senior Structures Engineer and be at the forefront of innovative aerospace solutions. In this pivotal role, you will lead the design and analysis of structural components for space vehicles, ensuring safety and performance in the demanding environment of space. You will collaborate with a passionate team of engineers and contribute to groundbreaking projects that push the boundaries of technology.

At Sift, we are pioneering the future of infrastructure for modern machines, transforming the way they are constructed, tested, and managed. Our innovative platform offers engineers unparalleled real-time observability over high-frequency telemetry, effectively eliminating bottlenecks and facilitating rapid, dependable development.Originating from our groundbreaking work at SpaceX on projects like Dragon, Falcon, Starlink, and Starship, Sift emerged from the need for advanced infrastructure to accommodate complex telemetry, debug flight systems, and ensure mission reliability. Our founding team, with expertise from SpaceX, Google, and Palantir, crafts solutions for mission-critical systems where precision and scalability are paramount.As a pivotal member of our engineering team, you will not only write code but also play a significant role in shaping the architecture, product direction, and culture of a company dedicated to addressing real engineering challenges. If you thrive on tackling intricate technical problems and aspire to build foundational systems that support complex machinery, we encourage you to apply.

Join Radiant Industries as a Senior Thermal Engineer, where you will play a crucial role in developing innovative thermal solutions for our cutting-edge projects. You will collaborate with a dynamic team of engineers and scientists to enhance product performance through advanced thermal management techniques.

Mattel, Inc. seeks a Senior Quality Engineer based in El Segundo. This role centers on upholding and improving quality standards across several product lines. The position plays a key part in ensuring that products meet expectations from development through production. Key responsibilities Use quality assurance methods and tools to enhance processes Monitor product quality at every stage, from development to production Collaborate with teams to ensure products are reliable and meet quality goals This role focuses on both maintaining current standards and identifying opportunities to raise the bar for product quality at Mattel.

About Matter IntelligenceMatter Intelligence is at the forefront of developing cutting-edge airborne and spaceborne sensing systems that integrate precision optics, innovative thermal architectures, spacecraft engineering, and AI-enhanced data analysis. Our advanced systems function effectively in challenging orbital and airborne environments, unlocking new possibilities for Earth observation capabilities.With a proven track record of delivering technologies to Mars for NASA/JPL, designing advanced sensors for U.S. defense, and establishing core infrastructure at OpenAI, our team is now focused on creating the next generation of sensing systems for both space and airborne applications.About the RoleWe are looking for a Senior Thermal Engineer who will take charge of the thermal architecture, analysis, and verification of our precision optical payloads and spacecraft systems. This role encompasses ownership of thermal performance from the initial concept stage through integration, testing, and, where applicable, on-orbit operations.You will be responsible for developing and maintaining intricate thermal models, steering thermal trade studies, supporting STOP performance, and collaborating closely with systems, optomechanical, electronics, and AI & T teams to ensure that flight hardware meets all performance requirements throughout every mission phase.This is a hands-on, analytical, and leadership-focused role suited for an engineer seeking significant technical ownership over hardware that operates in flight.Key ResponsibilitiesThermal Architecture & DesignDefine and lead the thermal architecture for optical payloads and spacecraft subsystems.Design both passive and active thermal control solutions, including radiators, heat pipes, thermal straps, insulation, and cryogenic interfaces.Translate mission-level thermal requirements into subsystem- and component-level designs.Support thermal trades to effectively balance performance, mass, power, and complexity.Thermal Modeling & AnalysisDevelop, maintain, and correlate detailed thermal models using industry-standard tools (e.g., Thermal Desktop, SINDA/FLUINT).Conduct steady-state and transient thermal analyses across all mission phases (launch, ascent, on-orbit hot/cold cases, safe modes).Perform in-depth thermal analysis of precision optical elements (mirrors, mounts, focal plane assemblies), including thermo-elastic distortion.Execute thermal assessments at the circuit card and chassis level.

Senior Materials Engineer (Metallurgy)Join Radiant Industries as a dynamic Senior Materials Engineer, where you'll be responsible for the testing and qualification of materials, particularly metals, for our innovative Kaleidos 1MW nuclear microreactor. We’re looking for an individual who takes pride in their work, is highly skilled in materials selection, testing, and analysis, and thrives in a fast-paced, collaborative environment. You will play a crucial role in ushering in the era of the world's first mass-produced, rapidly-deployable nuclear reactor.Responsibilities & DutiesPlan and execute comprehensive materials testing to derive essential material properties for informed design decisions.Spearhead the qualification of all metallic components utilized in the design of the Kaleidos reactor.Conduct rapid prototypic testing to mitigate risks associated with design and integration.Collaborate closely with the manufacturing team to develop and validate application-specific manufacturing processes including welding, brazing, coating, casting, and heat treatments.Provide expert advice on materials selection for various components within the Kaleidos project.Identify and manage equipment necessary for materials characterization and testing.Assess and ensure the quality and accuracy of material property data for our materials database.Define and enhance manufacturing processes to achieve the desired material properties.Required Qualifications & SkillsBachelor’s degree from an accredited institution in Materials Science and Engineering, or Mechanical, Aeronautical, Nuclear, or Chemical Engineering with a focus on materials science.5+ years of experience in the development, testing, and analysis of materials for challenging load scenarios and environments.Desired Qualifications & SkillsMaster’s or PhD degree in a related field is preferred.

Join Mattel, Inc. as the Senior Manager of Quality Engineering, where you will play a pivotal role in ensuring the highest standards of quality in our innovative products. In this dynamic position, you will lead and mentor a team of skilled engineers, driving quality initiatives that align with our commitment to excellence. Your expertise will directly contribute to enhancing product performance, reliability, and safety, making a meaningful impact on the lives of children and families around the world.

Engineering TechnicianJoin Radiant Industries as an Engineering Technician, where you will utilize a diverse array of skills in the fabrication and assembly of our innovative microreactor unit. Your role will be pivotal in constructing both large and small-scale test rigs, creating prototype components and tooling, and sourcing the necessary tools for assembly. You will be the fourth key technician on our team, necessitating a high level of autonomy and initiative. In our new El Segundo headquarters, you will manage our prototype shop, working with an assortment of tools across various shop activities, including machining, welding, metal forming, electrical work, and plumbing. This position offers you the chance to make a substantial technical impact as we strive to fuel a new reactor design for the first time in over 50 years by 2026.Key Responsibilities:Fabricate components to specifications using various shop equipment such as mills, lathes, welders, and hand tools.Lead the assembly and commissioning of test rigs and production builds.Conduct troubleshooting and root cause analysis for mechanical, electrical, thermal, and pneumatic issues.Collaborate with engineers to devise solutions and enhancements for hardware design, fabrication, and assembly processes.Maintain high operational standards regarding safety, reliability, and cleanliness.Perform additional tasks as required; versatility is essential in our small team environment.

Senior Nuclear EngineerJoin Radiant Industries as a Senior Nuclear Engineer! In this pivotal role, you will take the lead on modeling techniques and reactor physics calculations that drive neutronics parameters such as reactivity, kinetics parameters, and energy deposition distributions. These calculations are integral to our innovative Digital Twin simulation software. Your expertise will ensure the safety and reliability of our modeling methods, which are crucial for the commercialization of the first mass-produced nuclear reactor.Key Responsibilities:Lead the development of core neutronics models and reactor physics calculations, essential for Radiant’s transient safety analyses.Execute calculations of energy deposition distributions, reactivity coefficients, kinetics parameters, and control blade worths for integration into Digital Twin models.Verify modeling assumptions and evaluate the conservatism of neutronics models.Document methodologies for both technical and non-technical stakeholders.Support Verification & Validation (V&V) initiatives for the Digital Twin.Collaborate with teams across the company on reactor physics, shielding, and radiation detection analyses.Qualifications:Bachelor’s degree in Nuclear Engineering or a related discipline from an accredited institution.A minimum of 4 years of experience with Monte Carlo nuclear engineering software such as OpenMC, MCNP, Serpent, SCALE, etc.Proven ability to document analysis methods and assumptions effectively.Strong programming skills in any language, with a preference for Python.Preferred Qualifications:Familiarity with reactor kinetics.Basic understanding of thermal hydraulic principles.Experience in communicating complex information to cross-functional teams.Self-motivated with a strong sense of ownership for project outcomes.

Senior Mechanisms EngineerRadiant Industries is on the lookout for a dynamic and experienced Senior Mechanisms Engineer to spearhead the design and development of essential mechanisms within the innovative Kaleidos project. In this role, you will tackle unique engineering challenges to create efficient and dependable mechanisms that govern reactivity and activate critical safety features. Your responsibilities will encompass trade studies, material selection, in-depth structural analysis, assembly, integration, and rigorous testing. Your contributions will be vital in propelling the introduction of the first new commercial reactor design in over five decades by the year 2026.Key Responsibilities:Lead the design and development of crucial mechanisms such as control blade actuators and air jacket valves.Conduct comprehensive trade studies and formulate designs that align with program requirements.Execute detailed thermomechanical analysis (including static strength and durability/fatigue) and kinematic analysis to assess structural integrity and performance margins using both hand calculations and finite element analysis tools.Develop and implement manufacturing and assembly instructions along with test plans.Create and oversee a Bill of Materials (BOM).Identify and cultivate relationships with suppliers for necessary components.Manage schedules for subassembly design, manufacturing, and testing.Conduct risk analysis (FMEA) for subsystems.Gather requirements and provide insights to engineers across other functional areas through effective communication.Qualifications:Bachelor's degree in Mechanical or Aeronautical Engineering from an accredited institution.A minimum of 4 years of experience in mechanism design.Over 4 years of experience conducting stress analysis utilizing both hand calculations and finite element tools (such as Abaqus, Ansys, FEMAP, or equivalent).Desired Skills:Proficient in the design of multi-component assemblies using CAD software (NX or similar).Experience in designing hardware that underwent manufacturing, deployment, and iterative improvements.Familiarity with pneumatic system design.Knowledge in integrating electromechanical components such as motors or encoders.

About VardaLow Earth orbit is open for business. Varda is pioneering the advancement of commercial space infrastructure, from in-orbit pharmaceutical processing to dependable and cost-effective reentry capsules.From life-saving pharmaceuticals to enhanced fiber optics, a myriad of products utilized on Earth today can only be produced in space. Varda is driving innovation in the orbital economy by establishing both the products and infrastructure required for space to directly enhance life on Earth. Our mission is to expand the economic horizons of humanity.Our team is exceptionally equipped to achieve this objective, with leadership and personnel comprising veterans from SpaceX, Blue Origin, leading pharmaceutical companies, and Silicon Valley. Founded in January 2021 by Will Bruey and Delian Asparouhov, Varda is supported by esteemed investors including Khosla Ventures, Lux Capital, Founders Fund, Caffeinated Capital, General Catalyst, and Also Capital.Varda's headquarters is located in El Segundo, California, where we operate offices and a production facility for building, integrating, and testing our vehicles, equipment, and materials. Additionally, Varda has offices in Washington, DC, and Huntsville, AL.Join Varda and contribute to the creation of a thriving in-space ecosystem.

We are seeking a highly skilled and experienced Senior Thermal-Hydraulics Engineer to join our dynamic team at Radiant Industries. In this role, you will be responsible for designing, analyzing, and optimizing thermal-hydraulic systems to enhance our product offerings. Your expertise will play a crucial role in ensuring the efficiency and reliability of our engineering solutions.As a key member of our team, you will collaborate with cross-functional teams to develop innovative designs, conduct simulations, and perform experiments. If you are passionate about engineering and eager to take on new challenges, we invite you to apply!

About Varda SpaceUnlocking the Potential of Low Earth Orbit. At Varda, we are pioneering the advancement of commercial space infrastructure, innovating in areas from in-orbit pharmaceutical production to dependable and cost-effective reentry vehicles.With products ranging from life-saving medications to advanced fiber optics, we are committed to developing the technologies that can only be realized in the unique environment of space. Our mission is to enhance the orbital economy, creating products and infrastructure that directly benefit life on Earth.Our team is comprised of industry leaders and experts with backgrounds in SpaceX, Blue Origin, top pharmaceutical firms, and Silicon Valley tech. Founded in January 2021 by visionaries Will Bruey and Delian Asparouhov, we are supported by premier investors such as Khosla Ventures, Lux Capital, Founders Fund, and others.Headquartered in El Segundo, California, Varda features offices and a production facility dedicated to the development and testing of our vehicles, equipment, and materials. Our presence extends to Washington, DC, and Huntsville, AL.Join us at Varda and contribute to building a vibrant in-space ecosystem.

Role Overview Varda Space Industries is hiring a Senior Mechanisms Engineer focused on payload systems in El Segundo, California. This role leads the design, development, and testing of mechanisms that enable advanced payloads for space applications. What You Will Do Design, develop, and test mechanisms that support complex payloads Work closely with multidisciplinary teams to integrate mechanical systems Help ensure payload mechanisms meet quality and performance requirements

Senior Mechanical Engineer - Fluid SystemsRadiant Industries is on the lookout for an enthusiastic and experienced Senior Mechanical Engineer specializing in Fluid Systems. This pivotal role involves overseeing the design and development of critical Kaleidos fluid systems, guiding projects from initial design to production. These systems are essential for converting reactor core heat into electrical power.As a key member of our engineering team, you'll engage in trade studies, component selection, thermal hydraulic analysis, piping design, vendor evaluation, assembly, and rigorous testing. Your contributions will play a vital role in launching the first new commercial reactor design in over 50 years by 2026.Responsibilities:Lead the engineering process for fluid systems and components, including compressors, valves, and heat exchangers.Conduct complex thermal and fluid analyses to inform design choices, validate system performance, and maintain structural integrity using hand calculations and finite element analysis tools.Perform trade studies to enhance system performance and fulfill program requirements.Create and implement manufacturing and assembly instructions along with test plans.Manage and maintain a comprehensive Bill of Materials (BOM).Identify and cultivate relationships with suppliers for all components.Oversee the design, manufacturing, and testing schedules for subassemblies.Conduct risk analysis (FMEA) for subsystems.Gather requirements and provide guidance and constructive feedback to engineers across various disciplines.Qualifications:Bachelor’s degree in Mechanical, Materials, Aeronautical, Civil, or Structural Engineering from an accredited institution.Proven experience in fluid system architecture design.A minimum of 4 years of experience in designing, building, and testing fluid systems.In-depth knowledge of fluid dynamics and thermodynamics.Solid understanding of heat exchanger design and analysis techniques.