Mechanical Engineer, Senior

Why 9 Mothers?

Position Summary

Essential Duties

• Solve the hard mechanism problems. Take on the feed, action, drive, latching, and timing problems that are blocking a product, from first sketch through working hardware. Own the concept, the kinematic and dynamic analysis, the detailed design, and the test.
• Design for motion under load. Cams, linkages, gear trains, springs, ratchets, escapements, detents, and the interfaces between them. Get the forces, timing, and energy budgets right, and make the mechanism tolerant of the real-world conditions it will see.
• Prototype with your own hands. Machine, print, fit, and assemble your own test articles. Instrument them. Cycle them until they break, then explain exactly why.
• Diagnose by ear, by hand, and by data. Find the root cause of a jam, a stall, a noise, a wear pattern, or an intermittent failure, and separate what the hardware is telling you from what the drawing says it should be doing. Partner with our test engineer on high-speed video and instrumented testing when the failure is too fast to see.
• Kill bad ideas early. Bring the judgment to recognize when a concept will not survive contact with tolerances, contamination, temperature, or a soldier, and say so before we spend months finding out.
• Make it manufacturable. Design mechanisms that can be built repeatably with the processes and tolerances we can actually hold, and work with our manufacturing engineer and machine shop to get there. Produce drawings with GD&T that suppliers can build to.
• Work across disciplines. Collaborate with electrical, firmware, and controls on actuator selection, sensing, and the electromechanical interfaces where motion meets control.
• Support testing in the field. Go to the range. Watch the hardware run. Wrench on it when it fails, and bring back the findings that feed the next revision.

Requirements

• 10+ years of mechanical engineering experience with a clear track record of mechanism design on hardware that shipped and worked in the field.
• A demonstrated talent for mechanisms. You can look at a mechanism and see how it moves, where it binds, and what will wear. You can sketch a linkage or a cam profile that does what you want on the first or second try. We will ask you to show us examples of mechanisms you designed and to explain what went wrong with them.
• Fluency in kinematics and dynamics: linkage synthesis, cam design, gear train design, spring and energy storage design, impact and high-rate loading, tolerance and clearance analysis for moving assemblies, and the analysis tools to back it up. Multibody simulation experience is a plus; sound engineering judgment about when simulation is lying to you is a requirement.
• Deep practical knowledge of how mechanisms fail: friction and lubrication, wear, fatigue, backlash, fretting, galling, contamination, and thermal effects, and the material and surface-treatment choices that address them.
• Hands-on prototyping and troubleshooting skills. You are comfortable on a mill, a lathe, and a bench, and you have a history of taking machines apart and putting them back together, on the job and on your own time.
• Strong GD&T and drawing skills. You produce drawings that fully constrain a moving assembly and that suppliers can build to.
• The judgment to say no. You have seen enough clever ideas fail to know which ones will, and you are direct about it without being difficult.
• Efficient, low-ego, and easy to work with. You build rapport quickly and move work forward without drama.

Nice-to-Have

Benefits

• Meaningful Early Equity: You aren't just an employee; you are a foundational owner. Your contributions directly drive the value of your stake in the company.
• Direct Roadmap Influence: Forget the bureaucracy of big defense. You will have a seat at the table, directly shaping our product and technology trajectory from day one.
• Mission-Critical Work: We don't build for "what if." We build systems the Department of War actively needs to counter immediate, real-world threats.
• The Builder's Playground: Work in a brand-new lab fully optimized for rapid prototyping, equipped with NVIDIA Jetsons, high-end scopes, and 3-D printers.
• 100% Employer-Paid Premiums: We cover 100% of your medical, dental, and vision insurance premiums and cover 50% of healthcare premiums for your dependents.
• Unlimited PTO: We value results, not clock-watching. Take the time you need to stay sharp and recharge.
• Zero Red Tape: You have the autonomy to make technical decisions that would take months of committee approval at a larger firm.
• Austin-Based Culture: Join an onsite team in Austin, TX, where we prioritize high-bandwidth collaboration and rapid field-testing.
• Relocation Assistance: We want the best talent in the room. If you aren't in Austin yet, we’ll help you get here, to make your transition to the Silicon Hills seamless.

About the Interview