Application System Administrator (Control Systems) - L3

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.
By applying for this position, you acknowledge and agree that Horizontal Talent may contact you regarding your application using automated technology, including phone calls, SMS/text messages, or email, which may be delivered by our virtual AI recruiter, Alex.