9 Mothers Corporation

Building the Modern Battlefield

9 Mothers Defense is a defense technology company based in Austin, TX, focused on developing AI-enabled systems to counter unmanned aerial threats. Founded in 2024 and part of Y Combinator's Spring 2026 batch, the company is tackling the growing challenge of small Unmanned Aerial Systems (sUAS) on the modern battlefield. Their first product, EDDA, is a fully autonomous-capable counter-drone point-defense platform designed to detect, track, and neutralize fast-moving Group 1 drone threats. The system is engineered to be compact, low-power, and low-cost, making it suitable for deployment on vehicles, bases, or even carried by personnel.

A Culture of High-Bandwidth Collaboration

The culture at 9 Mothers is defined by its onsite, builder-centric ethos. They prioritize high-bandwidth collaboration and rapid field-testing, creating an environment optimized for quick iteration. With a "Zero Red Tape" philosophy, engineers report directly to the founders, granting them the autonomy to make technical decisions that would typically require months of committee approval at larger defense contractors. The workspace is described as a "Builder's Playground," featuring a brand-new lab equipped with NVIDIA Jetsons, high-end scopes, and 3-D printers, all designed for rapid prototyping.

What You'll Actually Do

Engineers at 9 Mothers work on mission-critical systems that the Department of Defense actively needs to counter immediate, real-world threats. The technology stack involves building robots, sensors, and the models to control them from scratch, utilizing a mix of Python and Rust on embedded hardware. Machine Learning and Computer Vision Engineers are responsible for designing, training, and deploying models that power the perception stack under strict Size, Weight, and Power (SWaP) constraints. The work involves real-time object detection, sensor fusion, and multi-object tracking of small, fast-moving targets. They do not rely on pre-built cloud APIs, LLMs, or RAG, meaning engineers must have a fundamental understanding of the problem space and the ability to build models from the ground up.

Compensation & Benefits

9 Mothers offers competitive compensation packages with significant early equity. Senior Engineering roles (such as Machine Learning and Computer Vision) offer salaries ranging from $150K to $250K, along with 0.01% to 5.00% equity depending on the role. Staff-level roles can reach up to $400K. The company covers 100% of medical, dental, and vision insurance premiums for employees and 50% for dependents. Additional benefits include unlimited PTO and relocation assistance to Austin, TX.

The Interview Process

The interview process at 9 Mothers is rigorous and practical, designed to assess both technical capability and cultural fit. It typically begins with a 30-minute application screening call. This is followed by a virtual technical interview, which may include a live coding test with the Director of Engineering or CTO (approximately 45 minutes). The core of the evaluation is a paid take-home consulting agreement ($500 for about 4-8 hours of work), allowing candidates to demonstrate their skills on realistic problems. After reviewing the take-home work, candidates have a virtual interview with the CEO, followed by an in-person visit to the Austin office before an offer is made.

Why Join / Why Not

Why Join: 9 Mothers is an ideal environment for hands-on builders who want to work on critical defense problems without the bureaucracy of traditional defense primes. The opportunity to shape the product roadmap directly, work with cutting-edge hardware, and receive meaningful early equity makes it highly attractive for engineers who thrive in fast-paced, autonomous environments.

Why Not: The onsite requirement in Austin, TX, and the intense focus on defense technology may not appeal to everyone. The work requires U.S. citizenship and the ability to pass a background check (or obtain a security clearance). Additionally, the startup environment demands a high level of ownership and the ability to build systems from scratch without relying on standard cloud infrastructure, which can be challenging for those accustomed to more established tech stacks.