Principal Software Engineer, Autonomous Defense

The posting, as Horizon3 wrote it

Get to Know Us

Horizon3 is a fast-growing, remote cybersecurity company dedicated to the mission of enabling organizations to proactively find and fix and verify exploitable attack vectors before criminals exploit them. Our flagship product, the NodeZeroTM platform, delivers production-safe autonomous pentests and other key assessment operations that scale across the largest internal, external, cloud, and hybrid cloud environments. NodeZero has been adopted by organizations of all sizes, from small educational institutions to government agencies and Global 100 enterprises. It is used by ITOps/SecOps teams, consulting pentesters, and MSSPs and MSPs.

We are a fusion of former U.S. Special Operations cyber operators, startup engineers, and formerly frustrated cybersecurity practitioners. We're committed to helping solve our common security problems: ineffective security tools, false positives resulting in alert fatigue, blind spots, "checkbox” security culture, cybersecurity skills shortage, and the long lead time and expense of hiring outside consultants. Collectively, we are a team of learn it alls, committed to a culture of respect, collaboration, ownership, and results.

What You'll Do

We are hiring a Principle Software Engineer to lead the technical work for NodeZero's defensive agents: the systems that translate proven attack paths into continuous actionable remediation.

You'll set direction alongside our AI researchers, who define what the agents should reason about, and lead the engineers who build the platform underneath them.

This is a technical leadership role without direct people management. You lead through architecture, code, design review, and mentorship, not through performance reviews and headcount. It is also not a pure architect role. You will write production code every week, review PRs from the engineers you lead, and partner closely with Product to sequence the right problems in the right order. You will be the person who both draws the system diagram on the whiteboard and commits the first slice of it to main.

RESPONSIBILITIES

LEADERSHIP & TEAM DEVELOPMENT

• Owns the end-to-end technical vision for the workstream and rallies the team around it — from blank doc through shipping, iterating, and deprecating.
• Production code contributions at Lead/Principle level in a modern backend language (Python, Go, Rust, or similar) in a service-oriented environment.
• Sets and raises the technical bar (design reviews, code quality, operational discipline) by example rather than by mandate.
• Mentors and enhances the engineers around them; builds the frameworks and architecture for others to do the best work of their careers.
• Holds the team accountable to outcomes rather than activity; surfaces risks and tradeoffs early and in writing.
• Serves as the durable technical interface between AI research and platform engineering, so research direction accounts for platform constraints early rather than at handoff

[…]
tructure is designed to be fair, competitive, and transparent, ensuring that every team member is recognized and compensated equitably across roles, levels, and locations.

In accordance with various State’s transparency regulations, we provide the following salary range information for this position:

• Base salary range: $255,000-$300,000 annually. The exact salary will be determined based on the selected candidate’s location, qualifications, experience, and relevant skills.
• Additional compensation: All full-time roles are eligible for an equity package in the form of stock options.

You Belong Here

Horizon3 is not just an equal opportunity employer - we are a community that values diversity, equity, and inclusion as fundamental principles of our culture and success. We are dedicated to fostering a workplace where everyone feels welcome and respected, regardless of race, color, religion, sex, national origin, age, disability, veteran status, sexual orientation, gender identity or expression, genetic information, marital status, or any other legally protected status by law.

Our commitment to diversity and inclusion means we strive to attract, develop, and retain a workforce that reflects the varied communities we serve. We believe that diverse perspectives drive innovation and strengthen our ability to create cutting-edge cybersecurity solutions. At Horizon3, every team member is valued and supported in an environment that encourages personal and professional growth.

We welcome candidates from all backgrounds and experiences, and we encourage all qualified individuals to apply. Come be a part of Horizon3, where your unique contributions are recognized, and your potential is limitless.

Other Duties

Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties or responsibilities that are required of the employee. Duties, responsibilities, and activities may change at any time with or without notice.