---
title: 'Senior Backend Engineer, Integrations at Horizon3 AI'
canonical: 'https://feeny.ai/job/senior-backend-engineer-integrations-horizon3-ai-united-states-2xa5w9tjx2p5'
type: 'job'
last_seen: '2026-11-07'
---

# Senior Backend Engineer, Integrations at Horizon3 AI

- **Company:** [Horizon3 AI](https://feeny.ai/companies/horizon3-ai)
- **Location:** United States
- **Employment:** full-time
- **Work type:** remote
- **Posted:** 2026-09-28
- **Last confirmed live:** 2026-11-07
- **Apply:** https://jobs.ashbyhq.com/horizon3ai/2f20ccd7-cdeb-44c0-8aef-3981be23602f

## 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

You'll be joining the Platform Integration Team (PIT Crew) — a high-impact group whose mandate is critical to the scalability and extensibility of the NodeZero platform. The PIT Crew's mission is to transform Horizon3's APIs and integrations from a collection of one-off vendor connectors into a consistent, documented, permission-aware platform. You'll build the systems that let customers connect NodeZero to the tools they already rely on across the security and IT ecosystem. This is a senior individual contributor role. You'll lead through technical judgment, cross-functional partnership, and high-quality execution — owning significant pieces of platform infrastructure while helping set the standard for the team.

In this role, you will:

- API Platform: evolving our internal GraphQL-federated API into a first-class, customer-facing product — with permissions, multi-account scoping, versioning, schema evolution, and documentation.
- Integration Platform: building and operating a shared Integration Router so new connectors can be configured and declared rather than built from scratch, with reusable authentication, health checks, and workflow execution.
- Security-Tool Integrations: shipping and maintaining integrations with the tools customers already use — CrowdStrike, Splunk, ServiceNow, Jira, Palo Alto, SentinelOne, and others in the SIEM, EDR, and ticketing ecosystem.
- MCP Platform: expanding our customer-facing MCP server and agentic workflow capabilities across US, EU, and Australia production environments, enabling customers to build their own AI-powered workflows atop NodeZero data.
- You'll also share on-call responsibility for a substantial production-observability footprint (Datadog, Kafka-triggered services, multiple environments), meaning you're not just shipping integrations — you're operating them.

## What You'll Be Responsible For

- Design and implement backend APIs in GraphQL — including federated subgraph development, schema evolution, and multi-account query scoping for MSSP and multi-subsidiary customers.
- Build and extend the Integration Router: connector libraries, workflow configuration, secrets management, vendor adapters, and Kafka-triggered dispatch services.
- Own production reliability for API and integration services: monitoring, alerting, deployment, vendor API drift, rate limits, retries, and safe failure handling.
- Contribute to the MCP platform and OAuth proxy layer, including tool authentication and agentic workflow support.
- Contribute production code that sets the standard for design quality, code quality, and operational rigor.
- Collaborate with frontend engineers, product managers, and security-domain teams (particularly the Pentest Data Platform) to deliver integrated customer experiences.
- Mentor junior and mid-level engineers on the team as it scales.

## What You'll Bring

- Ability to own and manage concurrent initiatives, with strong judgment in prioritization and time management.
- Self-directed and driven — capable of conceiving and implementing solutions independently and as part of a team.
- A strong desire to continuously learn new technologies in a fast-paced Agile environment.
- Excellent analytical and problem-solving skills, with attention to detail and a high bar for quality.
- Strong technical documentation ability to support an external developer audience.
- Effective communication and collaboration across engineering, product, and design.
- Interest in mentoring junior and mid-level engineers as the team grows.

Required Education / Experience

- Bachelor's Degree in Computer Science, Computer Engineering, or a related field.
- 7+ years of professional software engineering experience using modern object-oriented or functional languages (Python, Go, TypeScript, Java, Scala, C++, etc.).
- Experience building production applications on cloud platforms (AWS, Azure, GCP) using Docker and Kubernetes.

What Sets You Apart

- Expert proficiency in SQL, and experience with relational (PostgreSQL) and graph (Neo4j) database architectures.
- Hands-on experience building GraphQL backends, including federated graph architectures and schema evolution patterns.
- Experience designing and operating public API platforms — versioning, developer documentation, permission models, and multi-tenant access.
- Experience building or operating an integrations platform with reusable connector patterns, event-driven workflows (Kafka or similar), and asynchronous execution.
- Familiarity with OAuth/OIDC, service accounts, or machine identity patterns for programmatic API access.
- Experience integrating with third-party security or IT platforms — SIEMs, EDR tools, ticketing systems (e.g., CrowdStrike, Splunk, ServiceNow, Jira, Palo Alto), or workflow automation platforms.
- Experience with MCP, agentic frameworks, or other tool-protocol ecosystems.
- Production reliability experience: observability tooling (Datadog or similar), on-call ownership, vendor API drift handling, and safe failure design.
- Experience with customer-facing developer surfaces: CLI tooling, SDKs, or developer portals.

## 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: $170,000 - $235,000 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
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