Internship Python Mechanical Engineering Jobs in Boulder, CO

Mechanical Engineer - Advanced Manufacturing

Whether you call yourself a mechanical engineer, a manufacturing engineer, or just someone who loves turning designs into hardware, if you want to own how the world’s most advanced electric motors get built, read on.

About H3X Technologies

At H3X, we're building the most advanced electric motors in the world, powering the future of sustainable aviation, marine, industrial, and defense applications. Our motors range from 30 kW to 1 MW+ and are up to 3x lighter than competing platforms, driving a step change in electric propulsion technology.

Our team brings together some of the best minds from aerospace, defense, and motorsports, with deep expertise in electric machines, power electronics, material science, and advanced manufacturing. We're a small, fast-moving team doing hard engineering that matters, and we're looking for people who want to do the best work of their careers alongside us.

Why this role is different

You'll have real ownership from day one, direct access to the people making decisions, and the chance to see your work go from whiteboard to hardware, in flight, on the water, or in the field, in a matter of months, not years. We move fast, we learn fast, and we celebrate wins together. You've probably worked somewhere that moves fast and builds hard things or you're hungry to.

About the Role:

H3X is hiring Mechanical Engineers focused on advanced manufacturing across all levels (Associate to Staff) to develop and scale our manufacturing processes from early-stage prototypes through full production. You'll do hands-on process development and production support, bridging R&D and sustained manufacturing so new technologies can be built reliably, efficiently, and at scale. You'll take full ownership of a program or production area such as Stator Manufacturing, Rotating Assemblies, or Final Assembly, supporting both new product introductions and production scaling of existing products. Some positions lean more toward process development; others toward tooling, fixtures, and equipment.

What you'll do

• Develop, prototype, and mature novel manufacturing processes from concept through production deployment.

• Lead manufacturing readiness for new products: process development, work instructions, tooling design, subscale testing, prototype builds, and the transition from prototype to production.

• Own capacity planning and scalability for your production area; find the bottlenecks and implement the equipment, tooling, and workflow improvements that support forecasted demand.

• Design, validate, and deploy production tooling, fixtures, and assembly aids in SolidWorks to improve quality, throughput, and operator ergonomics.

• Resolve production issues through root-cause analysis and drive non-conformance investigations and CAPA to eliminate recurring defects.

• Build the systems, tooling, and workflows that make the whole team faster: the goal is to save the team time, not add process for its own sake.

• Partner with design, supply chain, quality, and operations to bake manufacturability into the product from the start.

What everyone needs

• Degree in Mechanical Engineering or similar (or equivalent hands-on experience)

• Strong grasp of engineering fundamentals, mechanical drawings, and GD&T

• CAD proficiency, SolidWorks preferred

• Bias to action, an ownership mentality, and a first-principles approach to problems

• Excellent written and verbal communication, strong attention to detail, and high emotional intelligence: you collaborate respectfully and empathetically

• Fundamentally curious and eager to learn quickly

Associate / early-career

You're a scrappy, hard-working self-starter who learns fast, runs toward problems, and would rather build and iterate than wait for perfect instructions. Internship, project, or team experience with real hardware is a plus.

Senior / Staff

You bring deep manufacturing experience scaling complex assemblies. Just as important, you build systems that save the team time rather than create overhead. You can walk a production area, identify which systemic improvements will actually move the needle, prioritize ruthlessly, and drive them to completion.

Additional Nice to Have Experience:

• Experience scaling complex assemblies to higher production volume

• Experience designing manufacturing floor layouts

• Understanding of electric motors or high-voltage systems

• Experience working in a startup environment

• Experience with ISO9001 and/or AS9100 standards

Compensation:

$90,000 - $200,000 based on experience (Associate to Staff Level). Offers are calibrated to level and experience.

Benefits

Robust benefits including medical, vision, dental, disability, and life insurance offerings, an employee equity incentive program, and a 401k program. Additional benefits include our gym membership stipend and outdoor recreation reimbursement program. We have an execution-based culture with flexible hours, flexible time off, 12 company holidays (including our company ski trip), monthly company events, and weekly catered team lunch on Fridays.

Our Values

Be Relentless Never give up, persevere until the job is done. Run toward problems, not away from them. Grit is key.

Gain insight through humility Approach every challenge with a learner’s mindset. Stay open to feedback, listen to others, and deepen your understanding through self-awareness. Put your ego aside and seek the truth in every discussion, especially when leading others.

Distill & Simplify Eliminate unjustified complexity and simplify wherever possible, whether in requirements, design, or execution. Use first principles thinking to distill every problem to its essence. Less is more.

Find your flow Engage fully and work with intention. Find the rhythm and deep focus that lets you do your best work. Discover your Ikigai - where your strengths, passions, and purpose meet and drive your personal fulfillment and team success. That is when the magic happens.

SEND (Solve, Evolve, Nail It, Deliver) Devise the best solution with the information at hand, test it, learn from it, and iterate quickly until you nail it. Nothing works perfectly the first time, but you should never hit the same issue twice. Stay laser-focused on solving customer problems and delivering solutions that create real value.

Equal Opportunity Employer

H3X is an equal opportunity-affirmative action employer and considers all qualified applicants for employment based on business needs, job requirements and individual qualifications, without regard to race, color, religion, sex, age, disability, sexual orientation, gender identity or expression, marital status, past or present military service or any other status protected by the laws or regulations in the locations where we operate.