Senior IT Systems Engineer

Horizon3

20h•$142,000 - $162,000•Remote

About The Position

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.

Requirements

Hands-on experience administering an identity/SSO platform (e.g., Okta) in a production environment, including access policies and app integrations
Experience configuring and maintaining email security controls, including SPF, DKIM, DMARC, and anti-phishing/anti-spam tooling
Experience administering a cloud email/collaboration platform (Google Workspace or Microsoft 365, or similar)
Hands-on experience administering enterprise network infrastructure (switches, routers, firewalls, VPN) in a production environment
Working knowledge of network security principles, including segmentation, firewall policy management, and VPN architecture
Experience troubleshooting complex network, identity, and email connectivity issues with minimal escalation
Experience documenting configurations, architecture diagrams, and operational runbooks
Able to scope and manage moderately complex projects end-to-end with little to no direction
Experience supporting a distributed or remote-first workforce
3–5 years of experience in systems administration, identity/security engineering, or network administration
Experience supporting a distributed or remote-first workforce
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

Nice To Haves

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

Responsibilities

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