Staff Backend Engineer, MSSP

Horizon3

Remote, United StatesFull-time$230,000–$270,000Posted Oct 30, 2026

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, 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 IT Ops/SecOps teams, consulting pentesters, and MSSPs and MSPs.

We are a fusion of former U.S. Special Operations cyber operators, startup engineers & operators, and formerly frustrated cybersecurity practitioners. We're committed to helping solve our common security problems: ineffective security tools and 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

As a Staff Backend Engineer on the MSSP & TRPM team, you’ll provide hands-on technical leadership for the NodeZero capabilities that enable partners to manage services across many customer environments. You’ll shape architecture for multi-tenant workflows, account hierarchies, delegated administration, client and sub-client management, and asset allocation or deprecation. You’ll guide designs that preserve tenant boundaries and give partners reliable ways to administer their customer relationships. Working across Product and Engineering, you’ll lead complex initiatives while remaining accountable for implementation quality and production outcomes.

Responsibilities

Set technical direction for partner and multi-tenant platform services, including account hierarchies, tenant isolation, delegated administration, and partner workflows.

Lead architecture and implementation of complex capabilities for client and sub-client management, asset allocation or deprecation, and partner administration.

Define patterns for secure data boundaries, API design, reliability, observability, and operational readiness.

Remain hands-on in complex technical work and help teams make decisions when requirements or tradeoffs are ambiguous.

Partner with Product, customer-facing teams, and adjacent engineering groups to align platform capabilities with partner needs.

Mentor engineers through design reviews, code reviews, pairing, and technical documentation.

Own complex production issues and drive improvements that strengthen service reliability and prevent recurrence.

What You’ll Bring

Ability to lead broad technical initiatives, establish direction, and build alignment across teams.

Strong judgment around tenant isolation, security, data integrity, reliability, and customer impact.

Clear communication and technical writing, including the ability to explain architecture and tradeoffs to both technical and non-technical partners.

A mentoring mindset and commitment to raising engineering practices across the organization.

Hands-on ownership of production services, including operational follow-through and continuous improvement.

Required Education / Experience

Bachelor’s degree in Computer Science, Computer Engineering, or a related field, or equivalent practical experience.

8+ years of professional software engineering experience, including deep experience with backend systems and APIs.

Track record of leading architecture or technical direction for production multi-tenant, platform, or distributed systems.

Strong understanding of data modeling, service reliability, and security boundaries in customer-facing systems.

Ability to influence decisions across teams, mentor engineers, and communicate technical tradeoffs clearly.

Experience building and operating cloud-hosted services and taking ownership of production outcomes.

Required Tech Stack Experience

Deep experience building backend services in a modern language such as Python, Go, Java, or TypeScript.

Strong SQL and relational data modeling, API design, and production service-operating experience.

Experience with cloud-hosted systems and containerized applications such as Docker; familiarity with Kubernetes or a comparable orchestrator.

Experience with every example technology is not required; depth in relevant areas and the ability to guide sound technical decisions are important.

Work Authorization & Security Clearance Requirements

[If applicable, otherwise delete section]

Only US persons can interview for this role due to security clearance requirements by our customer(s) and/or vendor(s). Employee must be eligible for and successfully secure a US Federal Security Clearance as a condition of employment.

What Sets You Apart?

Deep experience with MSP/MSSP, reseller, white-label, or partner software platforms.

Experience with delegated administration, parent/sub-client account models, tenant isolation, RBAC, and audit logs.

Strong proficiency in Python or Go, SQL/PostgreSQL, AWS, GraphQL, Docker, and Kubernetes.

Background in cybersecurity or third-party risk management, licensing, entitlements, or compliance-adjacent capabilities.

[Optional] Travel Required

We are a fully remote company, and this job may require up to 5% of travel to be successful.

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 $230,000 - $270,000 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.

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.

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, hair length 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.

Application Note

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.

Responsibilities

  • Set technical direction for partner and multi-tenant platform services, including tenant isolation and delegated administration.
  • Lead architecture and implementation of partner, client, and sub-client management capabilities.
  • Establish patterns for secure data boundaries, API design, reliability, observability, and operational readiness.
  • Lead complex technical work and guide decisions when requirements or tradeoffs are ambiguous.
  • Partner with Product, customer-facing teams, and engineering groups to align platform capabilities with partner needs.
  • Mentor engineers through design reviews, code reviews, pairing, and technical documentation.
  • Own production issues and drive improvements to service reliability.

Qualifications

  • Bachelor’s degree in Computer Science, Computer Engineering, a related field, or equivalent practical experience.
  • 8+ years of professional software engineering experience, including deep backend systems and API experience.
  • Experience leading architecture or technical direction for production multi-tenant, platform, or distributed systems.
  • Strong understanding of data modeling, service reliability, and security boundaries in customer-facing systems.
  • Experience building and operating cloud-hosted services and owning production outcomes.
  • Deep backend development experience in a modern language such as Python, Go, Java, or TypeScript.
  • Strong SQL, relational data modeling, API design, and production service-operating experience.
  • Experience with cloud-hosted systems and containerized applications such as Docker; familiarity with Kubernetes or a comparable orchestrator.

Benefits

  • Equity package in the form of stock options
  • Health, vision, and dental insurance for employees and their families
  • Flexible vacation policy
  • Generous parental leave
  • Remote work, with up to 5% travel

Skills mentioned

PythonBackend DevelopmentSQLPostgreSQLGraphQLAWSDockerKubernetesDistributed SystemsSystem Design

About Horizon3

Horizon3.ai answers the two most important questions in cybersecurity: If someone tried to compromise us, would we hold up? And, how do we withstand the onslaught of AI-powered attacks? Horizon3.ai’s NodeZero® shifts the advantage from attackers to defenders by giving organizations the power to fight AI with AI. The Proactive Security Platform autonomously tests your defenses at machine speed, safely finds and prioritizes exploitable attack paths, instantly verifies fixes, and drives a continuous loop so you can prove you’re resilient, not just hope you are. NodeZero, the World’s Best AI Hacker™, was built by an elite team of U.S. cyber veterans and has honed its skills over 225K production-safe tests, more than all manual pentests in history. More than 5,000 organizations including the NSA, CISA, Fortune 100 giants, and major healthcare providers trust Horizon3.ai to prioritize what matters and prove they’re ready for what’s next. Horizon3.ai has been recognized by Fast Company as one of the World’s Most Innovative Companies in 2026. The company ranked #3 overall on the 2025 Deloitte Technology Fast 500 and was named the #1 cybersecurity company on the Inc. 5000 in 2025. It has also been named to the Fortune Cyber 60 in both 2023 and 2025 and is a two-time Black Unicorn Award winner.

Computer and Network Security501-1,000 employeesSan Francisco, CA