Senior IT Systems Engineer

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 are seeking a security-minded IT Systems Engineer with a genuine passion for networking — someone equally comfortable hardening identity and email infrastructure as they are managing routing and firewall policy. This role is roughly 60% security, identity, and email systems and 40% network engineering.

You will own the controls that protect how our distributed workforce authenticates, communicates, and connects, while keeping the underlying network reliable and well-documented. This role partners closely with Security and the Help Desk team to resolve escalated issues and to keep network, identity, and email infrastructure aligned with company security standards.

This role will be responsible for.....

Administer and secure Okta (or equivalent IdP/SSO), managing authentication policies, access provisioning, and integration with downstream applications

Architecting, Administering and secure the company email/collaboration platform, including mail flow rules, spam/phishing filtering, DKIM/DMARC/SPF configuration, and data loss prevention policies

Own operations, monitoring, and incident response for network, email and identity security controls including firewall policy, and threat detection

Triage incidents and remediate or escalate per incident response procedures

Collaborate across teams (Security and Help Desk) to resolve escalated connectivity issues, support onboarding/offboarding, and ensure infrastructure remains aligned with security standards.

Evaluate and recommend improvements to identity architecture, email security posture, and related tooling

Administer and maintain network infrastructure: switches, routers, firewalls, and wireless access points while also supporting a distributed workforce, including capacity planning and performance monitoring

Design and implement network changes (VLANs, routing, firewall rule changes) with minimal disruption to business operations

Maintain accurate documentation of network topology, configurations, and email/identity security architecture

Manage vendor relationships and support contracts for network, firewall, identity, and email security tooling

Demonstrate a commitment to integrity, process improvement, and customer satisfaction

What You’ll Bring

Must have hands-on experience administering an identity/SSO platform (e.g., Okta) in a production environment, including access policies and app integrations

Must have experience configuring and maintaining email security controls, including SPF, DKIM, DMARC, and anti-phishing/anti-spam tooling

Must have experience administering a cloud email/collaboration platform (Google Workspace or Microsoft 365, or similar)

Must have hands-on experience administering enterprise network infrastructure (switches, routers, firewalls, VPN) in a production environment

Must have working knowledge of network security principles, including segmentation, firewall policy management, and VPN architecture

Must have experience troubleshooting complex network, identity, and email connectivity issues with minimal escalation

Must have experience documenting configurations, architecture diagrams, and operational runbooks

Must be able to scope and manage moderately complex projects end-to-end with little to no direction

Must have experience supporting a distributed or remote-first workforce

Minimum Education and Experience

3–5 years of experience in systems administration, identity/security engineering, or network administration

Experience supporting a distributed or remote-first workforce

Required Tech Stack Experience

Identity/SSO platform (e.g., Okta, or similar)

Email security gateway / anti-phishing tooling (e.g., Proofpoint, Mimecast, or similar)

Email/collaboration platform (Google Workspace or Microsoft 365, or similar)

Enterprise firewalls (e.g., Palo Alto, Fortinet, or similar)

Routing and switching (e.g., Cisco, Meraki, or similar)

Network monitoring tools

What Sets You Apart?

Relevant certifications such as Security+, CCNA, CCNP, or Okta certifications

Experience with SASE/SSE platforms or Zero Trust network architecture

Experience automating identity, network, or email security tasks via scripting (Python, PowerShell, or similar)

Experience in high-growth SaaS or cybersecurity companies

Travel Required

We are a fully remote company, and this job may require up to 15% 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: $142,000 - $162,000 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.

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 [or Total On-Target Compensation]: $XX - $XX annually . The exact salary will