Senior IT Systems Engineer

Horizon3.ai; United States; Remote; USD 142,000 - 162,000; Full time

Benefits offered by this job

Inclusive culture

Career growth

Innovative culture

Hybrid/Remote work

Competitive compensation

Health/vision/dental insurance

Flexible vacation & parental leave

Job summary

Horizon3 is a remote cybersecurity company pioneering autonomous pentests via the NodeZero platform. We seek a security-minded IT Systems Engineer to own identity, email, and network security for a distributed workforce while collaborating with Security and Help Desk teams.

You will administer Okta, manage email security, and oversee network infrastructure to ensure secure, reliable operations across cloud and on-prem environments.

Qualifications

• Hands-on experience with identity/SSO platforms in production.
• Experience configuring email security controls and anti-phishing tooling.
• Experience administering Google Workspace or Microsoft 365.
• Hands-on with enterprise network infrastructure (switches, routers, firewalls, VPN).
• Knowledge of network security concepts like segmentation and firewall policy.
• Ability to document configurations and runbooks.
• Capable of managing moderately complex projects with minimal direction.
• Experience supporting distributed or remote-first teams.

Responsibilities

• Administer and secure Okta or similar IdP/SSO for users and apps.
• Architect, administer and secure company email/collaboration platform and related security policies.
• Own operations, monitoring, and incident response for network, email and identity security controls.
• Triage incidents and remediate or escalate per IR procedures.
• Collaborate across Security and Help Desk to resolve connectivity issues and onboarding/offboarding.
• Evaluate and recommend improvements to identity architecture and email security posture.
• Maintain network infrastructure docs, topology diagrams, and runbooks.
• Manage vendor relationships and support contracts for security tooling.

Skills

Identity/SSO administration

Email security configuration

Email/calendar platforms

Enterprise network infra

Routing & switching

Firewalls

VPN architecture

Incident response

Documentation & runbooks

Remote workforce support

Tools

Okta

Proofpoint / Mimecast

Google Workspace

Microsoft 365

Palo Alto

Fortinet

Cisco Meraki

VPN

Network monitoring tools

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.

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 elevate 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 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, 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.