Senior Digital Signal Processing Engineer (Audio)
<p><strong>Location:</strong> Onsite — Austin, TX</p>
<p><strong>Employment Type:</strong> Direct Hire, Full-Time</p>
<p><strong>Job Title:</strong> Senior Digital Signal Processing Engineer (Audio)</p>
<p><strong>About 9 Mothers</strong></p>
<p>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.</p>
<p>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.</p>
<p><strong>Why 9 Mothers?</strong></p>
<p>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.</p>
<p><strong>Position Summary</strong></p>
<p>We are seeking a <strong>Senior Digital Signal Processing Engineer</strong> to own the stack that turns raw multichannel audio into reliable bearings and alerts. You will design algorithms to function in messy outdoor conditions, optimized for low-latency execution on edge hardware to ensure our systems react faster than the threat.</p>
<p><strong>Essential Duties</strong></p>
<ul>
<li>
<p><strong>Build the DSP Pipeline:</strong> Design and implement the full pipeline, including framing/STFT, filtering, coherence features, and noise/wind handling.</p>
</li>
<li>
<p><strong>Implement Beamforming & DoA:</strong> Compare and deploy approaches like MUSIC, ESPRIT, and MVDR, selecting the best strategy based on real-world field metrics.</p>
</li>
<li>
<p><strong>Hardware Partnership:</strong> Translate physical constraints (mic spacing, SNR limits) into algorithm decisions to ensure hardware and software are perfectly synced.</p>
</li>
<li>
<p><strong>Create Evaluation Infrastructure:</strong> Curate datasets and build replay harnesses and error taxonomies to answer "why did it fail" with data-driven certainty.</p>
</li>
<li>
<p><strong>Edge Optimization:</strong> Optimize for compute limits on CPU/GPU with deterministic behavior and robust fallbacks for high-stakes environments.</p>
</li>
</ul>
<p><strong>Requirements</strong></p>
<ul>
<li>
<p><strong>Experience:</strong> Demonstrated success delivering real-world multichannel audio, radar, or sonar systems validated on messy, imperfect data.</p>
</li>
<li>
<p><strong>Technical Depth:</strong> Strong beamforming/DoA fundamentals and sensitivity to calibration errors (phase errors, channel mismatch).</p>
</li>
<li>
<p><strong>Coding:</strong> Proficiency in Python and C++/Rust with the ability to productize, profile, and optimize code.</p>
</li>
<li>
<p><strong>Iteration:</strong> A mindset that iterates from measurements: logging → hypothesis → change → field verification.</p>
</li>
<li>
<p><strong>Compliance:</strong> U.S. Citizenship and the ability to pass a background check</p>
</li>
</ul>
<p><strong>Nice-to-Have</strong></p>
<ul>
<li>
<p>Embedded deployment experience (NVIDIA Jetson)</p>
</li>
<li>
<p>Acoustic tracking, temporal smoothing, or multi-source handling</p>
</li>
<li>
<p>Prior defense startup experience</p>
</li>
</ul>
<p><strong>Benefits</strong></p>
<ul>
<li>
<p><strong>Meaningful Early Equity:</strong> You aren't just an employee; you are a foundational owner. Your contributions directly drive the value of your stake in the company.</p>
</li>
<li>
<p><strong>Direct Roadmap Influence:</strong> Forget the bureaucracy of big defense. You will have a seat at the table, directly shaping our product and technology trajectory from day one.</p>
</li>
<li>
<p><strong>Mission-Critical Work:</strong> We don't build for "what if." We build systems the Department of War actively needs to counter immediate, real-world threats.</p>
</li>
<li>
<p><strong>The Builder's Playground:</strong> Work in a brand-new lab fully optimized for rapid prototyping, equipped with NVIDIA Jetsons, high-end scopes, and 3-D printers.</p>
</li>
<li>
<p><strong>100% Employer-Paid Premiums:</strong> We cover 100% of your medical, dental, and vision insurance premiums and cover 50% of healthcare premiums for your dependents.</p>
</li>
<li>
<p><strong>Unlimited PTO:</strong> We value results, not clock-watching. Take the time you need to stay sharp and recharge.</p>
</li>
<li>
<p><strong>Zero Red Tape:</strong> You report to the founders. You have the autonomy to make technical decisions that would take months of committee approval at a larger firm.</p>
</li>
<li>
<p><strong>Austin-Based Culture:</strong> Join an onsite team in Austin, TX, where we prioritize high-bandwidth collaboration and rapid field-testing.</p>
</li>
<li>
<p><strong>Relocation Assistance:</strong> 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.</p>
</li>
</ul>
<p><strong>About the Interview</strong></p>
<ol>
<li>
<p>Application screen phone call (30 min)</p>
</li>
<li>
<p>Virtual interview with co-founder/CTO + Director of Engineering (45 min via MS Teams)</p>
</li>
<li>
<p>Paid take-home consulting agreement ($500, ~4-8 hours)</p>
</li>
<li>
<p>Review work</p>
</li>
<li>
<p>Virtual interview with co-founder/CEO (45 min via MS Teams)</p>
</li>
<li>
<p>In-person visit to Austin</p>
</li>
<li>
<p>Offer</p>
</li>
</ol>
<p><strong>Employment Type:</strong> Direct Hire, Full-Time</p>
<p><strong>Job Title:</strong> Senior Digital Signal Processing Engineer (Audio)</p>
<p><strong>About 9 Mothers</strong></p>
<p>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.</p>
<p>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.</p>
<p><strong>Why 9 Mothers?</strong></p>
<p>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.</p>
<p><strong>Position Summary</strong></p>
<p>We are seeking a <strong>Senior Digital Signal Processing Engineer</strong> to own the stack that turns raw multichannel audio into reliable bearings and alerts. You will design algorithms to function in messy outdoor conditions, optimized for low-latency execution on edge hardware to ensure our systems react faster than the threat.</p>
<p><strong>Essential Duties</strong></p>
<ul>
<li>
<p><strong>Build the DSP Pipeline:</strong> Design and implement the full pipeline, including framing/STFT, filtering, coherence features, and noise/wind handling.</p>
</li>
<li>
<p><strong>Implement Beamforming & DoA:</strong> Compare and deploy approaches like MUSIC, ESPRIT, and MVDR, selecting the best strategy based on real-world field metrics.</p>
</li>
<li>
<p><strong>Hardware Partnership:</strong> Translate physical constraints (mic spacing, SNR limits) into algorithm decisions to ensure hardware and software are perfectly synced.</p>
</li>
<li>
<p><strong>Create Evaluation Infrastructure:</strong> Curate datasets and build replay harnesses and error taxonomies to answer "why did it fail" with data-driven certainty.</p>
</li>
<li>
<p><strong>Edge Optimization:</strong> Optimize for compute limits on CPU/GPU with deterministic behavior and robust fallbacks for high-stakes environments.</p>
</li>
</ul>
<p><strong>Requirements</strong></p>
<ul>
<li>
<p><strong>Experience:</strong> Demonstrated success delivering real-world multichannel audio, radar, or sonar systems validated on messy, imperfect data.</p>
</li>
<li>
<p><strong>Technical Depth:</strong> Strong beamforming/DoA fundamentals and sensitivity to calibration errors (phase errors, channel mismatch).</p>
</li>
<li>
<p><strong>Coding:</strong> Proficiency in Python and C++/Rust with the ability to productize, profile, and optimize code.</p>
</li>
<li>
<p><strong>Iteration:</strong> A mindset that iterates from measurements: logging → hypothesis → change → field verification.</p>
</li>
<li>
<p><strong>Compliance:</strong> U.S. Citizenship and the ability to pass a background check</p>
</li>
</ul>
<p><strong>Nice-to-Have</strong></p>
<ul>
<li>
<p>Embedded deployment experience (NVIDIA Jetson)</p>
</li>
<li>
<p>Acoustic tracking, temporal smoothing, or multi-source handling</p>
</li>
<li>
<p>Prior defense startup experience</p>
</li>
</ul>
<p><strong>Benefits</strong></p>
<ul>
<li>
<p><strong>Meaningful Early Equity:</strong> You aren't just an employee; you are a foundational owner. Your contributions directly drive the value of your stake in the company.</p>
</li>
<li>
<p><strong>Direct Roadmap Influence:</strong> Forget the bureaucracy of big defense. You will have a seat at the table, directly shaping our product and technology trajectory from day one.</p>
</li>
<li>
<p><strong>Mission-Critical Work:</strong> We don't build for "what if." We build systems the Department of War actively needs to counter immediate, real-world threats.</p>
</li>
<li>
<p><strong>The Builder's Playground:</strong> Work in a brand-new lab fully optimized for rapid prototyping, equipped with NVIDIA Jetsons, high-end scopes, and 3-D printers.</p>
</li>
<li>
<p><strong>100% Employer-Paid Premiums:</strong> We cover 100% of your medical, dental, and vision insurance premiums and cover 50% of healthcare premiums for your dependents.</p>
</li>
<li>
<p><strong>Unlimited PTO:</strong> We value results, not clock-watching. Take the time you need to stay sharp and recharge.</p>
</li>
<li>
<p><strong>Zero Red Tape:</strong> You report to the founders. You have the autonomy to make technical decisions that would take months of committee approval at a larger firm.</p>
</li>
<li>
<p><strong>Austin-Based Culture:</strong> Join an onsite team in Austin, TX, where we prioritize high-bandwidth collaboration and rapid field-testing.</p>
</li>
<li>
<p><strong>Relocation Assistance:</strong> 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.</p>
</li>
</ul>
<p><strong>About the Interview</strong></p>
<ol>
<li>
<p>Application screen phone call (30 min)</p>
</li>
<li>
<p>Virtual interview with co-founder/CTO + Director of Engineering (45 min via MS Teams)</p>
</li>
<li>
<p>Paid take-home consulting agreement ($500, ~4-8 hours)</p>
</li>
<li>
<p>Review work</p>
</li>
<li>
<p>Virtual interview with co-founder/CEO (45 min via MS Teams)</p>
</li>
<li>
<p>In-person visit to Austin</p>
</li>
<li>
<p>Offer</p>
</li>
</ol>