Principal Mechanical Engineer

Aurelius Systems
Aurelius Systems

Full-time

San Francisco, CA, USA

Posted on Aug 7, 2026

Who We Are:

Aurelius Systems is a VC backed defense tech startup building autonomous, edge deployed directed energy systems for counter-UAS. We build laser weapons to shoot down drones.

We're a small team of engineers, former US military, and subject matter experts scaling America's directed energy dominance. The first cost effective, reliable and robust laser weapon system.

Our namesake isn't an accident. Marcus Aurelius wrote about doing the work in front of you, every day, without excuses. Henry Ford didn't wait for permission to reinvent manufacturing. That's how we operate small team, unreasonable output, no hiding behind the unachievable.

In addition to our San Francisco lab, we opened our Detroit manufacturing hub and field test weekly on our own 400-acre private range.

The Role and Your Impact:

We need a Principal Mechanical Engineer to bring senior technical judgment across Archimedes hardware. You're a highly experienced builder who has taken systems the full way, from working prototype to hardware that ships and survives in the field, more than once. You know where systems break, where teams get stuck, and how to keep both moving.

You'll own mechanical architecture across the whole system, lead its integration with electrical, power, embedded and optics, and partner with the engineering leadership on architecture and roadmap.

What You'll Own:

  • Mechanical architecture across the full system and its integration with electrical, power, embedded, and optics

  • Technical decisions on the hardest problems, from concept through production readiness

  • Release and production process for hardware, with our Detroit manufacturing hub

  • Pattern recognition and technical review: surfacing risk early and catching what others miss

  • Hands-on execution when the problem needs your specific experience to solve fast

  • Design and manufacturing trades across cost, mass, reliability, schedule, and field performance

  • The technical bar for design reviews, documentation, and release standards

  • Mentorship by example. Engineers learn from watching you work, not from being managed by you

What We're Looking For:

  • 10+ years designing and shipping complex hardware systems

  • Track record taking systems the full cycle from prototype through manufacturing and deployment, more than once

  • Senior IC or technical leadership background at hardware companies that actually shipped

  • Deep mechanical expertise plus real judgment in at least one of electrical, power electronics, or embedded

  • Systems that had to survive real-world conditions

  • Comfort being the technical anchor on a small team, not the manager of a large one

Where you probably come from: Defense hardware, aerospace, F1 and high-performance automotive, maritime, robotics hardware, or directed energy programs.

We want to talk if: You've been the person a hardware team leaned on to get a system from prototype to production, and you still like doing the hardest part yourself.

Not a fit if: You're a people manager without recent hands-on work, your experience is purely consumer, or you've spent your career on one narrow subcomponent.

Nice to Haves:

  • Directed energy, laser or high-power systems

  • Defense or aerospace program experience with MIL-STD or equivalent qualification

  • Founder or founding engineer background at a hardware company

  • Manufacturing depth: you've stood up production lines or worked closely with the manufacturers who do

  • Active security clearance or ability to obtain one

Education:
BS, MS or PhD in Mechanical, Aerospace or related field. What you've built matters more than where you went to school.

How You Operate:

  • Extreme bias for action. You'd rather build a prototype tomorrow than model it for a month

  • You characterize your own systems before the field does

  • Comfortable with ambiguity and fast iteration in a startup environment

  • You debug from first principles, not intuition alone

  • Clear communicator across mechanical, electrical, optical, and software teams

  • Self directed. You identify what needs to happen next and do it without being told

Why Join Aurelius Systems:

  • Build more in 1 month than most engineers build in 1 year. We field test weekly. Your work goes downrange, not into a filing cabinet.

  • Career velocity is real. At ~10 engineers, there are no layers between you and impact.

  • Work on a problem that actually matters. Small cheap drones are changing warfare. Our laser systems are the asymmetric answer — infinite magazine, near zero cost per shot, scalable to every base, border, facility, and truck.

  • Join the densest defense startup ecosystem in the country. California is where the next generation of defense companies are being built.

How We Work:

Core hours are Monday through Friday, 9 to 6. When we're sprinting toward a demo or field test, the team ramps up — nights, weekends, whatever it takes to ship. When the sprint lands, we ramp down. We don't manufacture intensity for show.

Benefits:

  • Competitive salary and equity

  • United Health Care medical, dental, and vision coverage

  • Flexible 18 days PTO plus 5 sick days

  • Travel to field test events and range days

  • Covered daily lunches and office snacks and drinks

  • E-bike and scooter stipend up to $500

  • Direct access to leadership and real ownership over your work

Export Control Notice:

This role requires access to export-controlled information or items that require U.S. Person status. As defined by U.S. law, individuals who are any one of the following are considered to be a U.S. Person: (1) U.S. citizens, (2) legal permanent residents (a.k.a. green card holders), and (3) certain protected classes of asylees and refugees, as defined in 8 U.S.C. 1324b(a)(3).