[Hiring] Senior IT Systems Engineer @Horizon3

Role Description

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.

• Own the controls that protect how our distributed workforce authenticates, communicates, and connects, while keeping the underlying network reliable and well-documented.
• Partner 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.
• Administer and secure Okta (or equivalent IdP/SSO), managing authentication policies, access provisioning, and integration with downstream applications.
• Architect, administer, 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.

Qualifications

• 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.

Requirements

• 3–5 years of experience in systems administration, identity/security engineering, or network administration.
• Experience supporting a distributed or remote-first workforce.

Benefits

• 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.