Join a fast-paced control systems environment where your expertise in Windows, Linux, virtualization, and infrastructure support will help keep critical systems available around the clock. This L3 System Administrator role offers the opportunity to work on complex technology supporting operational reliability, security compliance, and continuous improvement.

Responsibilities

• Administer and maintain Windows and Linux server environments, ensuring stability, availability, and performance
• Support virtualization platforms, server provisioning, physical hardware lifecycle activities, and routine infrastructure maintenance
• Manage Nutanix and VMware-based environments, including VDI operations and related support tasks
• Monitor infrastructure health, performance trends, and utilization, and help resolve issues before they affect operations
• Apply security baselines, remediate compliance gaps, and support audit and reporting activities
• Implement patches and software updates using enterprise tools such as SCCM and Red Hat Satellite
• Provide tier-3 engineering support and business continuity support for control system infrastructure
• Collaborate with application, network, security, and functional teams to support daily operations and projects
• Participate in an on-call rotation to support control system environments
• Contribute to disaster recovery, fault tolerance, and continuity planning efforts

Skills

• At least 8 years of experience in system administration or closely related infrastructure support roles
• Strong hands-on experience with Windows Server and Linux administration
• Practical knowledge of Active Directory, DNS, DHCP, Group Policy, IIS, ADFS, and related core services
• Experience with Nutanix Prism Central, VMware vSphere, vRealize Suite, vRA, vRO, and Horizon View
• Solid troubleshooting skills across virtualization, server resources, and enterprise infrastructure platforms
• Experience supporting highly available and disaster recovery environments
• Working knowledge of security compliance requirements and operational best practices
• Strong PowerShell scripting ability and experience using automation to improve efficiency
• Understanding of RAID management, array controllers, backup tools, and command-line utilities
• Ability to work effectively across teams and communicate clearly with technical and business stakeholders

Preferred Skills

• Experience supporting operations technology or control system environments
• Familiarity with NERC CIP requirements and similar regulatory standards
• Experience with Microsoft clusters and load balancing
• Background in hardware break/fix support, OEM coordination, and platform upgrades or migrations
• Knowledge of data center environments, including hardware placement, racking, and cabling
• Experience working with Dell or HP hardware and remote connectivity tools
• Strong analytical skills with the ability to quickly assess issues, identify dependencies, and implement solutions

Horizontal is committed to fostering an inclusive, respectful, and welcoming environment where everyone has the opportunity to contribute and succeed. We value diverse perspectives and are dedicated to equitable hiring practices that help build stronger teams and better outcomes.