---
title: 'Senior Detection Engineer (EDR), Autonomous Defense at Horizon3 AI'
canonical: 'https://feeny.ai/job/senior-detection-engineer-edr-autonomous-defense-horizon3-ai-united-states-6n3wjspxctzj'
type: 'job'
last_seen: '2026-11-07'
---

# Senior Detection Engineer (EDR), Autonomous Defense at Horizon3 AI

- **Company:** [Horizon3 AI](https://feeny.ai/companies/horizon3-ai)
- **Location:** United States
- **Employment:** full-time
- **Work type:** remote
- **Posted:** 2026-09-18
- **Last confirmed live:** 2026-11-07
- **Apply:** https://jobs.ashbyhq.com/horizon3ai/b7292d93-0f57-4c29-9ec5-f75fc4110bc5

## Job description

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 Autonomous Defense 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, and detection coverage measurement.
- Strong working knowledge of MITRE ATT&CK and detection coverage frameworks, and a clear view of where they help and where they mislead.
- Solid understanding of post-compromise attacker behavior and how each surfaces in endpoint and identity telemetry.

## PRODUCT & COLLABORATION

- Demonstrated experience shaping a product or platform as a domain expert, whether in a security vendor, an internal tooling team, or a detection engineering function.
- Ability to influence without authority. You will not manage the engineers or own the roadmap, and you will still be expected to move both.
- Exceptional technical writing. Most of your leverage here comes from written artifacts — requirements, methodology docs, labeling guides, tuning content.
- Comfort translating between audiences: engineers, AI researchers, product managers, SOC analysts, and executives.

## TECHNICAL FLUENCY

- Enough scripting ability, ideally Python, to query APIs, inspect telemetry, and prototype an analysis.
- Comfort with SQL and with reasoning over large volumes of event and telemetry data.

## Perks of Horizon3

- Inclusive Team: We value diversity and promote an inclusive culture where everyone can thrive.
- Growth Opportunities: Be part of a dynamic and growing team with numerous career development opportunities.
- Innovative Culture: Work in a collaborative environment that encourages creativity and out-of-the-box thinking.
- Hybrid & Remote Work: We embrace a mix of remote and hybrid work models depending on role and location, including our Chicago office, where some roles require regular in-office presence.
- Competitive Compensation: We offer competitive salary, equity and benefits. Our benefits include health, vision & dental insurance for you and your family, a flexible vacation policy, and generous parental leave.

## Compensation and Values

At Horizon3, we believe that our people are our greatest asset, and our compensation philosophy reflects this core value. We are committed to fostering an environment where all employees feel valued, respected, and rewarded for their contributions. Our compensation structure 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: $195,000-$230,000 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.

## About Horizon3 AI

## Company Overview
- **One-liner**: Horizon3.ai provides an autonomous penetration testing platform (NodeZero) that safely hacks production environments to identify and fix exploitable attack paths using AI.
- **Entity Type**: Private (Series D – latest funding round in 2026, led by Prosperity7 Ventures)
- **Headquarters**: San Francisco, California, United States (447 Battery Street, San Francisco, CA 94111)
- **Founded**: 2019
- **Founders**: Snehal Antani (Co-Founder & CEO); founded by a mix of US Special Operations, US National Security, and cybersecurity industry veterans

## Core Business
- **Primary industry**: Cybersecurity (autonomous penetration testing, vulnerability management, continuous security validation)
- **Target customers**: B2B – large enterprises, Fortune 100, government agencies (NSA, CISA), healthcare providers, financial services, manufacturing, education, public sector
- **Mission**: “Turn the map around” – using the attacker’s perspective to help enterprises prioritize defensive efforts. The company aims to shift the advantage from attackers to defenders by fighting AI with AI.

## Products & Services
- **[NodeZero®](https://horizon3.ai/)**: Autonomous penetration testing SaaS platform. Safely runs real attack techniques in production environments (no agents, no disruption). Discovers and chains exploitable vulnerabilities, misconfigurations, harvested credentials, and dangerous defaults across external, identity, on-prem, cloud, and Kubernetes attack surfaces. Also includes Active Directory password auditing and phishing impact testing. Continuously validates fixes and repeats autonomously.

## Market Standing
- **Valuation**: Not publicly disclosed
- **Key Metrics**: 
  - Annual Revenue: **$35.5M** (per LinkedIn)
  - Total Funding: **$187M** (per LinkedIn) / **$181M** (per CB Insights – conflicting reports; both cited)
  - **225,000+** production-safe tests completed
  - **5,000+** customers
- **Notable Investors/Partners**: 
  - SignalFire (lead in Seed, Series A, Series B)
  - Craft Ventures (lead Series C)
  - Prosperity7 Ventures (lead Series D – 2026)
- **Growth Signals**:
  - Ranked **#1 in Security** on the 2025 Inc. 5000 list
  - **#3 overall** on the 2025 Deloitte Technology Fast 500
  - Fast Company’s **Most Innovative Companies** (2026) – #1 in Security
  - Named to the **Fortune Cyber 60** (2023 & 2025)
  - Two-time **Black Unicorn Award** winner
  - Headcount grew **115.5% YoY** to 341 employees (LinkedIn)
  - Active job postings up **168.2% YoY**; operates in 14 countries

## Competitive Advantages
- **AI-driven autonomous testing** that learns from hundreds of thousands of tests and uses the right AI (ML, GenAI) for each problem – delivers evidence-based results with **zero hallucinations**.
- **Production-safe** – zero downtime across all production tests, trusted by the world’s most sensitive high-security environments (NSA, CISA, Fortune 10, major healthcare).
- **No agents required** – fully self-service SaaS, safe to run continuously.
- **Real attack techniques** – not a scanner; shows actual attacker paths and impact.
- **Rapid verification** – instantly confirms fixes and repeats the cycle, enabling a continuous validation loop.

## Strategic Focus
- **Continuous validation** – driving a loop of test-fix-verify-repeat autonomously.
- **Fighting AI with AI** – building NodeZero to operate at machine speed against AI-powered attacks.
- **Global expansion** – already in 14 countries, with active hiring in EMEA, APAC, and the Americas.
- **Scaling the team** – 59 active job postings (as of mid-2026), with emphasis on engineering, sales, and customer success roles.

## Why Work Here
- **Culture**: Rated **5.0/5.0 on LinkedIn** (76 reviews) with perfect scores for Culture (5.0), Career (4.9), Compensation (4.7), and Work-Life (4.6). Described as a “kick-ass organization hell bent on disrupting an industry” with a team of “motivated learn-it-alls.”
- **Work Policy**: Remote-friendly (most roles listed as remote, HQ in San Francisco, CA). Offers flexibility across time zones.
- **Notable Perks** (from Built In and LinkedIn):
  - Comprehensive healthcare (medical, dental, vision, FSA)
  - Life insurance, disability insurance
  - 401(k) with company matching
  - Equity and employee stock purchase plan
  - Generous parental leave and family medical leave
  - Performance bonuses
  - Job training, conferences, and customized development tracks
  - Promotion policies and career growth support
- **Engineering Culture**: Built by US Special Operations and National Security veterans. Emphasis on high autonomy, real-world impact, and cutting-edge AI/security work. “If you want to be part of a kick-ass organization hell bent on disrupting an industry and keeping attackers at bay, let’s talk.”

## Sources
1. [horizon3.ai – Homepage](https://horizon3.ai/)
2. [horizon3.ai – About/Team](https://horizon3.ai/about-us/)
3. [LinkedIn – Horizon3.ai Company Page](https://www.linkedin.com/company/horizon3ai)
4. [Built In – Horizon3.ai Careers & Perks](https://builtin.com/company/horizon3ai)
5. [CB Insights – Horizon3.ai Profile](https://www.cbinsights.com/company/horizon-3-ai)

## Other roles at Horizon3 AI

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- [Senior Attack Engineer, GCP](https://feeny.ai/job/senior-attack-engineer-gcp-horizon3-ai-united-states-p7dypj66skxv) — United States
- [Senior Attack Engineer, Kubernetes](https://feeny.ai/job/senior-attack-engineer-kubernetes-horizon3-ai-united-states-8bbsrmqpg924) — United States
- [Senior Attack Engineer, OCI](https://feeny.ai/job/senior-attack-engineer-oci-horizon3-ai-united-states-06y0k0t6a5p9) — United States
- [Staff Backend Engineer, Internal](https://feeny.ai/job/staff-backend-engineer-internal-horizon3-ai-united-states-eccvzb53mpb7) — United States
- [Senior Sales Engineer (SLED)](https://feeny.ai/job/senior-sales-engineer-sled-horizon3-ai-united-states-agqan5xzy6d6) — United States
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- [Engineering Manager, Internal Attack](https://feeny.ai/job/engineering-manager-internal-attack-horizon3-ai-united-states-tx9j8q1pkfsx) — United States
- [Senior Account Executive, SLED - New York](https://feeny.ai/job/senior-account-executive-sled-new-york-horizon3-ai-new-york-2d49m7hyp482) — New York, NY
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