Staff Defensive Security Software Engineer

Horizon3 is an innovative, rapidly growing cybersecurity company on a mission to help organizations proactively identify, fix, and verify exploitable vulnerabilities before they can be leveraged by cybercriminals. Our flagship product, NodeZero™, delivers autonomous pentests and security assessments that scale acros...

Our team blends former U.S. Special Operations cyber operators, startup engineers, and seasoned cybersecurity professionals. Together, we’re tackling the industry's toughest challenges: ineffective tools, false positives, alert fatigue, skills shortages, and the high costs and long timelines associated with traditio...

As a fully remote company, we prioritize flexibility and require a minimum 25Mbps broadband connection.

As a Security Engineer on the Tripwires team, you'll combine deep security domain expertise with hands-on full-stack development to design, prototype, and ship new security capabilities within NodeZero. You'll partner with product managers and designers to identify high-impact opportunities, and work alongside product engineers to quickly turn those ideas into MVPs and production features. Day-to-day work spans product research, threat-informed design, and feature development — with a particular focus on honeytoken and honeypot creation, deployment, and detection logic for Tripwires and adjacent products like Rapid Response. By building these capabilities, you'll deepen customer engagement with our platform and deliver novel solutions that measurably improve their security posture.
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.

In any materials you submit, you may redact or remove age-identifying information such as age, date of birth, or dates of school attendance or graduation. You will not be penalized for redacting or removing this information.

Technical Leadership: Owns the end-to-end technical vision for the workstream and rallies the team around it — from blank doc through shipping, iterating, and deprecating.
Software Engineering: Production code contributions at Lead/Staff level in a modern backend language (Go, Rust, Python, or similar) in a service-oriented environment.
Self-Motivation: The ability to work independently with minimal supervision, demonstrating initiative and a high level of energy.
Collaboration: Work closely with other cross-functional partners to build and improve our product portfolio
Communication: Strong technical writing and documentation skills, with the ability to convey findings and methodologies to both technical and non-technical stakeholders.
Technical Design: Proficiency in designing, presenting, and evaluating technical solutions, ensuring high-quality software and secure development practices.
Team Leadership:
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; Build 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.
Product-Minded Technical Leadership:
Translates ambiguous product goals into concrete technical roadmaps.
Partners closely with PM — comfortable in PRD reviews, not just sprint planning.
Sequences an MVP without painting the team into a corner.
Python: Expert-level proficiency in large-scale Python software development.
Network Security: Deep experience with network security topics such as reconnaissance and lateral movement.
Windows Experience: Proficiency with Active Directory, Windows authentication, and other windows internals
Network Protocols: Strong understanding of network protocols such as SMB and WMI and their intricacies, including their role in exploitation vectors.
Database Experience: Experience with relational (Postgres) or graph (Neo4j) database systems.
Security Experience: Minimum of 4 years of experience in building offensive or defensive security solutions, ideally in endpoint, threat detection, or low-level systems.
Education: Bachelor's Degree in Computer Science, Computer Engineering or related field.
Equivalent experience may be considered if demonstrable through proof-of-concept write-ups, published vulnerability research, or similar achievements.
OSCP (Offensive Security Certified Professional), GCWN (GIAC Certified Windows Security Administrator) or equivalent certifications.
Previous experience in red teaming or penetration testing, incident response, detection engineering, deception technologies, or other deeply technical roles with relevant skill sets.
Previous experience working on large-scale software projects.
Experience administering, attacking, or defending cloud environments.
Knowledge of and experience with Docker and containerization technologies.
Familiarity with identity and directory services such as Active Directory, Entra ID, or Okta.
Familiarity with cloud authentication and authorization technologies such as Azure Service Principals or AWS IAM.
We are a fully remote company, and this job may require up to 5% of travel to be successful.