Lead Systems Engineer (Audio)

Location: Onsite — Austin, TX

Employment Type: Full-Time

Job Title: Lead Systems Engineer (Audio)

About 9 Mothers

The modern battlefield has changed. Cheap, autonomous suicide drones have turned the tactical advantage upside down, and the world is looking for a solution. At 9 Mothers, we aren’t just "innovating"—we are building the shield.

Backed by top-tier investors, we develop AI powered machines designed to intercept and neutralize Group 1/sUAS threats in real-time. Our flagship product is a low-power, counter-drone system built for the edge—on vehicles, at bases, or in a soldier's pack.

Why 9 Mothers?

While others build for "awareness" or "long-term research," we build for the immediate survival of those in harm’s way. We are a team of hackers, engineers, and mission-driven builders who value field-ready capability over polished slide decks. If you want to see your code or hardware in the field next month—not next year—this is your playground.

Position Summary

We are seeking a Lead Systems Engineer (Audio) to build the acoustic platform that makes everything else possible. You will be responsible for the "ears" of our autonomous csUAS platforms, selecting microphones, designing enclosures, and solving synchronization challenges to ship a robust real-time capture stack that works in harsh outdoor environments.

Essential Duties

• Architect the Array: Lead microphone selection (self-noise, dynamic range) and geometry tradeoffs (spacing vs. aliasing) while making critical mechanical decisions regarding wind protection and vibration isolation.

• Own Multichannel Acquisition: Manage clocking, sync, drift, and channel mapping to ensure "it never randomly breaks" reliability and strict latency budgets.

• Design Calibration: Develop rigorous procedures for phase/gain matching, timing offsets, and automated health tests to account for temperature and aging.

• Ship Baseline Pipelines: Implement dependable first-pass bearing/confidence outputs (e.g., GCC-PHAT, SRP-PHAT) with proper instrumentation.

• Build Field Tooling: Create infrastructure for logging, replay, and ground-truth procedures to enable rapid failure triage and regression testing.

• Product Integration: Deliver real-time modules with clear interfaces and diagnostics that integrate seamlessly with the broader autonomy stack.

Requirements

• Experience: Proven track record of shipping real-time audio or timing-sensitive sensor systems into production or field deployments.

• Acoustic Mastery: Hands-on understanding of mic physics, including SNR, directivity, propagation/multipath, and how wind/handling noise appears in logs.

• Programming: Strong implementation skills in C++ or Rust, with Python for tooling and analysis.

• Hardware Systems: Experience with digital mic interfaces (I2S/TDM/PDM), multichannel ADCs, and PTP concepts on embedded Linux/Jetson platforms.

• Compliance: U.S. Citizenship and the ability to pass a background check

Nice-to-Have

• Prior defense startup experience

• Security clearance or ability to obtain one

• Passion for building robots or engineering projects as a hobby

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 report to the founders. 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

1. Application screen phone call (30 min)

2. Virtual interview with co-founder/CTO + Director of Engineering (45 min via MS Teams)

3. Paid take-home consulting agreement ($500, ~4-8 hours)

4. Review work

5. Virtual interview with co-founder/CEO (45 min via MS Teams)

6. In-person visit to Austin

7. Offer