Demo

Senior Tooling Engineer

radiant
El Segundo, CA Full Time
POSTED ON 12/15/2025
AVAILABLE BEFORE 4/30/2026

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 failsafe microreactor that can be transported anywhere power is needed and run for up to five years without the need to refuel. 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 utilizes modern software engineering to rapidly achieve safe, factory-built microreactors that leverage existing, well-qualified materials. Founded in 2020, Radiant is on track to test its first reactor next year at the Idaho National Laboratory, with initial customer deliveries beginning in 2028.

Senior Tooling Engineer

Radiant is seeking a highly motivated senior tooling engineer who will be working closely with design engineers and the manufacturing team to develop and innovate custom tooling to build and assemble our microreactor system. You will be part of the early team that develops production tooling for the factory that will mass produce, fuel, and refuel Kaleidos.

Responsibilities and Duties

  • Partner with design and manufacturing engineers to develop innovative production tooling for fabricating and assembling complex mechanisms and structures. 
  • Design, analyze, and fabricate tooling that enables semi-remote operations for fueling/defueling of the reactor. 
  • Identify and develop appropriate suppliers for tooling components, fabrication. 

Required Skills and Qualifications

  • Bachelor’s degree from an accredited institution in mechanical, manufacturing, or other related engineering discipline. 
  • 4 years of experience in mechanical tooling design and fabrication of multi-component assemblies in CAD (NX or similar). 
  • Solid understanding of Geometric Dimensioning & Tolerancing (GD&T) with experience applying it to fabrication drawings.

Desired Skills and Qualifications

  • Master’s degree from an accredited institution in mechanical, manufacturing, or other related engineering discipline. 
  • Proficiency with both “hand calc” analytical methods and higher fidelity finite element-based analysis methods. 
  • Self-motivated with strong organizational, written, and oral communication skills. 
  • Experience with custom machine design; electromechanical systems, motors, actuators, linear rails, bearings, lifting/rigging, etc. 
  • Strong problem-solving skills and attention to detail. 
  • Demonstrated ability to work collaboratively with design and operations teams. 

Additional Requirements

  • Must be willing to work extended hours and weekends as necessary to achieve company goals. 
  • Must work 100% onsite at El Segundo HQ. 

Total Compensation and Benefits

Radiant's new hire compensation package includes base salary, substantial equity grants, and comprehensive benefits. Total compensation and level are determined through a holistic evaluation of your interview performance, experience, education, and qualifications. 

Benefits and Perks for Eligible Employees:

  • Stock: Substantial incentive stock plan for all full-time employees.
  • Medical: 100% premium coverage for base Silver level plan for employee 50% premium coverage for dependents. Platinum plans available.
  • One Medical: Sponsored memberships for eligible employees and their dependents.
  • Vision: 100% premium coverage for top tier plan 50% for dependents.
  • Dental: 100% premium coverage for top tier plan (including orthodontia) 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.

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.

Salary.com Estimation for Senior Tooling Engineer in El Segundo, CA
$170,136 to $212,987
If your compensation planning software is too rigid to deploy winning incentive strategies, it’s time to find an adaptable solution. Compensation Planning
Enhance your organization's compensation strategy with salary data sets that HR and team managers can use to pay your staff right. Surveys & Data Sets

What is the career path for a Senior Tooling Engineer?

Sign up to receive alerts about other jobs on the Senior Tooling Engineer career path by checking the boxes next to the positions that interest you.
Income Estimation: 
$143,168 - $187,631
Income Estimation: 
$165,786 - $219,848
Income Estimation: 
$143,168 - $187,631
Income Estimation: 
$165,786 - $219,848
Income Estimation: 
$81,530 - $107,803
Income Estimation: 
$101,553 - $129,430
Income Estimation: 
$101,553 - $129,430
Income Estimation: 
$118,984 - $155,144
Income Estimation: 
$118,984 - $155,144
Income Estimation: 
$143,168 - $187,631
View Core, Job Family, and Industry Job Skills and Competency Data for more than 15,000 Job Titles Skills Library

Job openings at radiant

  • radiant El Segundo, CA
  • Radiant is an El Segundo, CA-based startup building the world’s first mass-produced, portable nuclear microreactors. The company’s first reactor, Kaleidos,... more
  • 14 Days Ago

  • radiant El Segundo, CA
  • Radiant is an El Segundo, CA-based startup building the world’s first mass-produced, portable nuclear microreactors. The company’s first reactor, Kaleidos,... more
  • 16 Days Ago

  • radiant El Segundo, CA
  • Radiant is an El Segundo, CA-based startup building the world’s first mass-produced, portable nuclear microreactors. The company’s first reactor, Kaleidos,... more
  • 16 Days Ago

  • radiant El Segundo, CA
  • Radiant is an El Segundo, CA-based startup building the world’s first mass-produced, portable nuclear microreactors. The company’s first reactor, Kaleidos,... more
  • 3 Days Ago


Not the job you're looking for? Here are some other Senior Tooling Engineer jobs in the El Segundo, CA area that may be a better fit.

  • k2spacecorporation Los Angeles, CA
  • K2 is building the largest and highest-power satellites ever flown, unlocking performance levels previously out of reach across every orbit. Backed by $450... more
  • 25 Days Ago

  • K2 Space Corporation Los Angeles, CA
  • K2 is building the largest and highest-power satellites ever flown, unlocking performance levels previously out of reach across every orbit. Backed by $450... more
  • 1 Month Ago

AI Assistant is available now!

Feel free to start your new journey!