About the role

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're hiring a Senior Detection Engineer to be the blue team voice inside the Defensive Agent team. You'll sit between Product and Engineering as the person who defines what "correct" means. When an attack technique is detected, you decide what remediation that claim requires. Your judgment becomes the ground truth. This is not a coding role and it is not a product management role. Product owns the roadmap, Engineering owns the implementation, and our AI researchers own how the agents reason. You own the domain truth all three depend on, and you make it concrete enough to build and measure against. If you've spent your career being the person in the room who knows how the tools really behave, this is a seat where that knowledge teaches a system instead of firefighting alerts. PRODUCT DIRECTION & REQUIREMENTS - Partner with Product to turn EDR effectiveness and tuning ambitions into concrete, buildable requirements. - Translate blue team workflows and pain into prioritized product outcomes, and push back when a proposed feature or agent behavior would not hold up in a real SOC. - Define acceptance criteria for detection, effectiveness, and tuning features, and validate releases against them before customers see them. - Serve as the standing domain reference for Engineering and AI research: available for design reviews, technique questions, and vendor behavior questions. EDR & DETECTION DOMAIN OWNERSHIP - Own deep, current knowledge of the major EDR and endpoint platforms at the console, policy, telemetry, and API level. - Maintain fluency in how detection logic, prevention policy, exclusions, and tuning actually work in each product, including the differences between default and hardened configurations. - Define the vendor-specific policy semantics, so a recommended change means the same thing across platforms that model it differently. - Track platform changes, new detection capabilities, and vendor guidance, and keep our coverage model current as vendors ship. - Define what a correct tuning recommendation looks like and grade agent output against that standard. - Partner with the Attack team so technique coverage and detection expectations stay grounded in current adversary tradecraft. WHAT YOU'LL BRING EDR & BLUE TEAM EXPERTISE - 6+ years in detection engineering, security operations, incident response, or threat hunting, with meaningful time spent as a practitioner rather than an advisor. - Hands-on operational experience administering and tuning EDR platforms in production — writing detections, managing policy and exclusions, and investigating real alerts. - Deep understanding of what a SOC actually does with EDR output. - Fluency in false positive and false negative tradeoffs, alert fatigue