Join a fast-paced operations technology team as an Application System Administrator supporting critical control system environments in Dallas, Texas. This onsite, 6-month opportunity is ideal for a hands-on professional who enjoys solving complex technical challenges, improving system reliability, and supporting 24/7 operations in a highly regulated environment.

Responsibilities

• Support ongoing maintenance, upgrades, patches, and configuration changes across control system application environments
• Help define test approaches and validate code or system updates before production deployment
• Assess risks and operational impacts tied to system changes and communicate findings to stakeholders
• Coordinate planned outages and maintenance activities to minimize disruption to critical operations
• Partner with vendors and internal teams to manage issues, tickets, troubleshooting, and remediation efforts
• Monitor system health, performance, and utilization trends, and help address anomalies and service concerns
• Support security baseline compliance, audit readiness, and remediation activities aligned with applicable policies and standards
• Assist with tier-3 engineering support and business continuity efforts for control system applications
• Work closely with infrastructure, network, security, and functional teams to support daily operations
• Participate in an on-call rotation to support control system environments

Skills

• At least 8 years of experience in control system, OT, or closely related technology environments
• Strong system administration background with Windows Server and Linux operating systems
• Working knowledge of Active Directory, utility communication protocols such as ICCP, DNP3, and OPC, and data networks
• Experience with virtualization platforms such as Nutanix, Hyper-V, or VMware
• Hands-on troubleshooting and diagnostics experience in enterprise or operations technology environments
• Understanding of patching, maintenance, high availability, and disaster recovery practices
• Ability to support SSL/TLS encrypted communications between system components and external connections
• Experience with scripting and automation using Python, PowerShell, bash/shell, batch scripting, JSON, XML, CALC development, and Git
• Knowledge of backup tools, remote connectivity tools, and data center hardware, including racking and cabling
• Strong collaboration, communication, and vendor management skills

Preferred Skills

• Experience in utility operations technology or control system environments
• Familiarity with NERC CIP compliance requirements and related remediation processes
• Experience supporting control center applications in highly available or disaster recovery environments
• Ability to analyze dependencies and quickly resolve technical issues in a critical production setting
• Comfort working in a results-driven, highly collaborative team environment

Horizontal is committed to fostering a diverse, equitable, and inclusive workplace where everyone feels respected, supported, and empowered to contribute. We welcome applicants from all backgrounds and encourage qualified individuals to apply.