Principal Design Engineer Jobs
Principal Design Engineer jobs are open across aerospace, automotive, consumer electronics, medical devices, and industrial manufacturing, with specializations in systems engineering, mechanical design, and electrical design, at every level from senior engineer to distinguished principal. Find a role that fits below and apply directly.
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Showing 5 of 448+ Principal Design Engineer jobs
About Radiant
Radiant is an El Segundo, CA-based company building the world's only mass-produced, transportable nuclear microreactors. The U.S. grid is under growing strain, with power demand accelerating, driving higher utility costs, rising carbon emissions, and interconnection backlogs. Radiant has a solution, transportable, on-site power. Our first reactor, Kaleidos, is 1 megawatt: small enough to be factory-built, transported by land, sea, or air, and deployed wherever power is needed. 1 MW can power 1000 homes for five years. Ship it back and we refuel for a 20 year operating life. We made energy a product that can be used for critical infrastructure like military bases, data centers, hospitals, and remote sites, as well as the commercial main street businesses that keep America running. Founded in 2020, Radiant is under contract to deliver power to the U.S. Army, Navy and Air Force and has signed pre-order agreements with Equinix, with deployments beginning in 2028.
About the Role
Radiant is seeking a Principal Mechanical Design Engineer, Turbomachinery to serve as the Responsible Engineer for the turbomachinery within our nuclear-driven power generation system. This role owns the mechanical design, integrity, and performance of the core rotating assembly at the heart of our 1MW closed-loop Brayton cycle.
You will define and drive the mechanical architecture of high-speed rotating hardware operating at extreme temperatures, pressures, and rotational speeds. As a deeply technical individual contributor, you will set direction for rotor dynamics, structures, bearings, seals, and system integration while working closely with electrical, thermal, and manufacturing teams.
This is a hands-on, high-ownership role focused on technical excellence, sound engineering judgment, and delivering reliable, production-ready turbomachinery.
Responsibilities & Duties:
Technical Ownership & System Architecture
Serve as Responsible Engineer for the turbomachinery mechanical system.
Own the mechanical architecture and design strategy for high-speed rotating assemblies.
Lead rotor dynamics, structural integrity, and life analysis for rotating components and assemblies.
Define and flow down requirements from system-level constraints including thermal, structural, and operational environments.
Make key technical decisions on rotor layout, shafting, bearings, seals, materials, and clearances.
Ensure designs meet performance, reliability, safety, and regulatory requirements.
Establish and uphold standards for mechanical design rigor, analysis quality, and documentation.
Mechanical Design & Analysis
Lead detailed design of turbomachinery components including rotors, shafts, housings, and support structures.
Test and validate turbomachinery, driving model correlation, risk reduction, and performance verification.
Perform and review structural and thermal analysis to ensure integrity under high-speed and high-temperature operation.
Define tolerances, fits, stack-ups, and alignment strategies for precision rotating assemblies.
Partner with electrical engineering on alternator integration, including electromagnetic and structural coupling.
Cross-Functional Integration
Partner closely with turbomachinery aero, motor design, thermal, manufacturing, and test teams.
Ensure seamless integration between turbine, compressor, and alternator subsystems.
Drive clear interface definitions across mechanical, electrical, and thermal boundaries.
Collaborate with manufacturing to ensure designs are producible, inspectable, and scalable.
Engage with suppliers on technically critical components and design decisions.
Prototyping, Testing & Validation
Support assembly, integration, and test of turbomachinery hardware.
Define validation strategies including spin testing, thermal testing, and system-level operation.
Lead root cause analysis and drive design iteration for test failures or performance gaps.
Remain hands-on in hardware bring-up, troubleshooting, and refinement.
Technical Influence
Act as a subject matter expert in turbomachinery mechanical design and rotating systems.
Provide technical guidance and design reviews across the team without direct people management responsibility.
Influence engineering direction through deep expertise, data-driven decisions, and strong judgment.
Contribute to technical roadmap, risk identification, and mitigation strategies.
Required Qualifications & Skills:
B.S. in Mechanical Engineering or related field.
10+ years of experience designing high-speed rotating machinery (turbines, compressors, or similar systems).
Deep expertise in structural analysis and mechanical design of turbomachinery.
Experience with bearings, seals, and high-speed shafting design.
Expert-level proficiency with analysis tools (e.g., ANSYS) and advanced use of NX and Teamcenter for complex design, simulation, and product lifecycle management.
Strong understanding of tolerancing, GD&T, and precision mechanical assembly.
Experience owning hardware through design, build, and test cycles.
Hands-on experience with assembly, integration, and troubleshooting of turbomachinery.
Strong system-level thinking and mechanical intuition.
Excellent engineering judgment and decision-making capability.
Ability to influence without authority across cross-functional teams.
Clear communicator capable of articulating complex technical concepts.
High ownership mindset and accountability for hardware outcomes.
Ability to operate effectively in a fast-paced, first-of-a-kind development environment.
Desired Qualifications & Skills:
Experience with closed-loop Brayton cycle systems or similar energy systems.
Familiarity with high-temperature materials and extreme environment design.
Experience integrating mechanical systems with high-speed electric machines.
Prior experience as a Responsible Engineer for complex hardware.
Experience scaling hardware from prototype to production.
Additional Requirements:
Must be willing to work extended hours and weekends as necessary to accomplish our mission.
Must work 100% onsite at El Segundo HQ.
Benefits and Perks
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.
Nuclear Engineering Certificate Program: 100% covered educational program with Penn State University, for eligible employees, to rapidly upscale into nuclear.
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 full-time 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: recruiting@radiantnuclear.com.
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.
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: $200,500 - $314,475
About Radiant
Radiant is an El Segundo, CA-based company building the world's only mass-produced, transportable nuclear microreactors. The U.S. grid is under growing strain, with power demand accelerating, driving higher utility costs, rising carbon emissions, and interconnection backlogs. Radiant has a solution, transportable, on-site power. Our first reactor, Kaleidos, is 1 megawatt: small enough to be factory-built, transported by land, sea, or air, and deployed wherever power is needed. 1 MW can power 1000 homes for five years. Ship it back and we refuel for a 20 year operating life. We made energy a product that can be used for critical infrastructure like military bases, data centers, hospitals, and remote sites, as well as the commercial main street businesses that keep America running. Founded in 2020, Radiant is under contract to deliver power to the U.S. Army, Navy and Air Force and has signed pre-order agreements with Equinix, with deployments beginning in 2028.
About the Role
Radiant is seeking a Principal Mechanical Design Engineer, Turbomachinery to serve as the Responsible Engineer for the turbomachinery within our nuclear-driven power generation system. This role owns the mechanical design, integrity, and performance of the core rotating assembly at the heart of our 1MW closed-loop Brayton cycle.
You will define and drive the mechanical architecture of high-speed rotating hardware operating at extreme temperatures, pressures, and rotational speeds. As a deeply technical individual contributor, you will set direction for rotor dynamics, structures, bearings, seals, and system integration while working closely with electrical, thermal, and manufacturing teams.
This is a hands-on, high-ownership role focused on technical excellence, sound engineering judgment, and delivering reliable, production-ready turbomachinery.
Responsibilities & Duties:
Technical Ownership & System Architecture
Serve as Responsible Engineer for the turbomachinery mechanical system.
Own the mechanical architecture and design strategy for high-speed rotating assemblies.
Lead rotor dynamics, structural integrity, and life analysis for rotating components and assemblies.
Define and flow down requirements from system-level constraints including thermal, structural, and operational environments.
Make key technical decisions on rotor layout, shafting, bearings, seals, materials, and clearances.
Ensure designs meet performance, reliability, safety, and regulatory requirements.
Establish and uphold standards for mechanical design rigor, analysis quality, and documentation.
Mechanical Design & Analysis
Lead detailed design of turbomachinery components including rotors, shafts, housings, and support structures.
Test and validate turbomachinery, driving model correlation, risk reduction, and performance verification.
Perform and review structural and thermal analysis to ensure integrity under high-speed and high-temperature operation.
Define tolerances, fits, stack-ups, and alignment strategies for precision rotating assemblies.
Partner with electrical engineering on alternator integration, including electromagnetic and structural coupling.
Cross-Functional Integration
Partner closely with turbomachinery aero, motor design, thermal, manufacturing, and test teams.
Ensure seamless integration between turbine, compressor, and alternator subsystems.
Drive clear interface definitions across mechanical, electrical, and thermal boundaries.
Collaborate with manufacturing to ensure designs are producible, inspectable, and scalable.
Engage with suppliers on technically critical components and design decisions.
Prototyping, Testing & Validation
Support assembly, integration, and test of turbomachinery hardware.
Define validation strategies including spin testing, thermal testing, and system-level operation.
Lead root cause analysis and drive design iteration for test failures or performance gaps.
Remain hands-on in hardware bring-up, troubleshooting, and refinement.
Technical Influence
Act as a subject matter expert in turbomachinery mechanical design and rotating systems.
Provide technical guidance and design reviews across the team without direct people management responsibility.
Influence engineering direction through deep expertise, data-driven decisions, and strong judgment.
Contribute to technical roadmap, risk identification, and mitigation strategies.
Required Qualifications & Skills:
B.S. in Mechanical Engineering or related field.
10+ years of experience designing high-speed rotating machinery (turbines, compressors, or similar systems).
Deep expertise in structural analysis and mechanical design of turbomachinery.
Experience with bearings, seals, and high-speed shafting design.
Expert-level proficiency with analysis tools (e.g., ANSYS) and advanced use of NX and Teamcenter for complex design, simulation, and product lifecycle management.
Strong understanding of tolerancing, GD&T, and precision mechanical assembly.
Experience owning hardware through design, build, and test cycles.
Hands-on experience with assembly, integration, and troubleshooting of turbomachinery.
Strong system-level thinking and mechanical intuition.
Excellent engineering judgment and decision-making capability.
Ability to influence without authority across cross-functional teams.
Clear communicator capable of articulating complex technical concepts.
High ownership mindset and accountability for hardware outcomes.
Ability to operate effectively in a fast-paced, first-of-a-kind development environment.
Desired Qualifications & Skills:
Experience with closed-loop Brayton cycle systems or similar energy systems.
Familiarity with high-temperature materials and extreme environment design.
Experience integrating mechanical systems with high-speed electric machines.
Prior experience as a Responsible Engineer for complex hardware.
Experience scaling hardware from prototype to production.
Additional Requirements:
Must be willing to work extended hours and weekends as necessary to accomplish our mission.
Must work 100% onsite at El Segundo HQ.
Benefits and Perks
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.
Nuclear Engineering Certificate Program: 100% covered educational program with Penn State University, for eligible employees, to rapidly upscale into nuclear.
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 full-time 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: recruiting@radiantnuclear.com.
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.
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: $200,500 - $314,475
See All 448+ Principal Design Engineer Jobs
Find roles that match your experience and apply in just a few clicks.
Find JobsPrincipal Design Engineer Job Market
Who's Hiring
- Northrop Grumman39
- Renesas17
- Raytheon15
- Micron Technology13
- Celero Communications13
Top Industries Hiring
- Electronics & Hardware41
- Technology & Software12
- Manufacturing7
- Consulting & Professional Services7
- Energy2
What Employers Look For
The qualifications that appear most often in principal design engineer jobs.
- Bachelor's or master's degree in mechanical, electrical, or systems engineering
- Eight or more years of progressive design engineering experience with increasing responsibility
- Proficiency in CAD or EDA tools such as CATIA, SolidWorks, Creo, or Altium Designer
- Demonstrated experience leading design reviews, including PDR and CDR, to successful completion
- Experience applying GD&T, tolerance analysis, and design for manufacturability principles to production hardware
- Familiarity with industry standards such as IPC, MIL-STD, ISO, or ASME depending on sector
Tips for Your Principal Design Engineer Job Search
Tailor your resume to design ownership
Principal design engineer roles expect evidence of full design ownership, not just contribution. Rewrite each bullet to show you led the concept, owned the trade studies, and drove the design to release. Reviewers discard resumes that read like team-player narratives.
Lead with cross-functional influence on your portfolio
Hiring managers at the principal level want proof you shaped decisions beyond your own discipline. Highlight instances where your design choices resolved conflicts between manufacturing, procurement, and product requirements, not just technical elegance in isolation.
Apply early to roles that fit
Migrate Mate lists principal design engineer openings from across the United States in one place, so you can find roles that match your discipline and apply directly to each listing without having to piece together results from multiple sources.
Filter openings by design phase and tool stack
Principal roles vary enormously between early concept work and sustaining engineering. Read job descriptions for clues like 'new product introduction,' 'NPI,' or 'sustaining.' Match your strongest phase to the posting and name the relevant tools, whether that is CATIA, Creo, SolidWorks, or Altium, in your application.
Prepare a design decision narrative for interviews
Most principal design engineer interviews include a deep technical review of one past project. Prepare a structured account of a design decision where you evaluated competing approaches, explain your reasoning, and describe what you would change with hindsight. Interviewers probe for the depth of your engineering judgment, not just the outcome.
Negotiate scope and charter, not just compensation
At the principal level, your offer negotiation should include clarity on design authority, budget ownership, and reporting structure. Ask directly which design decisions require sign-off above you and what your charter covers. Ambiguity here creates friction within months of starting.
Principal Design Engineer Jobs: Frequently Asked Questions
Which companies are hiring the most principal design engineers?
The most active employers for principal design engineers right now are Northrop Grumman, Renesas, and Raytheon, and the most openings are in California, Texas, and Massachusetts, based on current listings on Migrate Mate as of November 2026. Aerospace, defense, and medical device companies consistently post at this level year-round.
How many principal design engineer jobs are remote?
About 56% of principal design engineer openings are fully remote or hybrid as of November 2026, though this varies significantly by discipline. Software-adjacent design roles and systems architects working in digital or embedded domains see the highest remote share, while roles tied to physical hardware, lab access, or manufacturing floors remain predominantly on-site.
How do you become a principal design engineer?
Most principal design engineers progress through senior engineer roles by accumulating full ownership of complex design programs rather than just contributing to them. Building a record of leading design reviews, resolving cross-functional trade-offs, and mentoring junior engineers signals readiness for the principal level. Developing depth in a recognized specialty, such as thermal management, RF systems, or structural analysis, accelerates the path considerably.
Can you get hired as a principal design engineer with limited senior experience?
It is possible if your experience demonstrates design ownership and technical leadership even at smaller scope. Employers respond to candidates who can point to a specific system or subsystem they owned end-to-end, defended in design reviews, and released to production. Gaps in years are less disqualifying than gaps in design authority, so frame your application around the decisions you made, not just the tasks you completed.
What does the principal design engineer interview process look like?
Most processes run three to four stages. An initial call with a recruiter or hiring manager focuses on background and role fit. A technical screen follows, often involving a design problem or a walkthrough of a past project. Finalists typically present a portfolio or case study to a panel that includes engineering leadership and cross-functional stakeholders. Some employers add a whiteboard or take-home design exercise before the offer stage.
Where can I find and apply to principal design engineer jobs?
You can find and apply to principal design engineer jobs on Migrate Mate, which lists current openings from across the United States. Search for roles that match your discipline, industry, and preferred location, then apply directly to each listing. No intermediaries are involved, and your application goes straight to the employer's process.
See All 448+ Principal Design Engineer Jobs
Find roles that match your experience and apply in just a few clicks.
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