Systems Admin Sr Adv (TS/SCI with Poly Required) with Security Clearance

Job Category: Systems Administration Requisition Number: SYSTE002229 Posting Details *

• Posted: July 29, 2026
• Full-Time
• On-site
• Salary Range: $124,092.80 USD to

$207,251.20 USD Job Details Description GCI embodies excellence, integrity and professionalism. The employees supporting our customers deliver unique, high-value mission solutions while effectively leverage the technological expertise of our valued workforce to meet critical mission requirements in the areas of Data Analytics and Software Development, Engineering, Targeting and Analysis, Operations, Training, and Cyber Operations. We maximize opportunities for success by building and maintaining trusted and reliable partnerships with our customers and industry. At GCI, we solve the hard problems. As a Senior Systems Administrator, a typical day will include the following duties: Position supports both medium-sized business network and small program networks with multiple users on several different domains. Requires responsive and active management to include all system administrator duties related to servers and end user devices.  Demonstrated knowledge of and experience with installing and maintaining software and hardware is essential. Must work closely with information assurance (IA) team and be skilled in scanning tools (Nessus, Rapid 7, SCAP, NMAP) and isolating and mitigating any vulnerabilities (WSUS). Implementing controls per NIST 800 series of standard publications (800-171, 800-171A, 800-53, 800-37) employing the risk management framework to include FedRAMP and Government Community Cloud. Advises senior leadership on IT procurement, and asset management, conducts research on tools that streamline business processes, and automate repeatable functions. Must work well under pressure and be capable of meeting deadlines in an environment where priorities can shift to adapt to evolving missions, goals, and objectives (Agile focus). Experience mentoring more junior administrators with possibility of providing supervisory oversight, if desired.

Primary Responsibilities

• Collaborate with peers, co-workers and customers by using Teams, Outlook, telephone, or any other tools available in the work environment.
• Provide IT customer service, create, unlock, assign permissions and roles to accounts.
• Conduct daily, weekly, and monthly scans on systems.
• Apply patches, updates and any other mitigation actions.
• Attend meetings with support staff, and program managers to identify priorities.
• Investigate and troubleshoot any IT issues.
• Develop and maintain system documentation.
• Install, modify, and repair computer hardware and software including networking gear.
• Support program and organizational logistics/procurement and property accountability.
• Perform daily system monitoring, verifying the integrity and availability of all hardware, server resources, systems and key processes, reviewing system and application logs, and verifying completion of scheduled events such as backups.
• Maintain standalone systems (patches, virus definitions, etc.) A candidate must be a US Citizen and requires an active/current TS/SCI with Polygraph clearance.

Equal Opportunity Employer / Individuals with Disabilities / Protected Veterans  Qualifications Skills Required Security+ Advanced Preferred A+ Advanced ITIL Advanced Network+ Advanced Linux Intermediate CCNA Advanced Behaviors Required Team Player
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Works well as a member of a group Detail Oriented
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Capable of carrying out a given task with all details necessary to get the task done well Preferred Innovative
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Consistently introduces new ideas and demonstrates original thinking Functional Expert
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Considered a thought leader on a subject : Motivations Required Self-Starter
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Inspired to perform without outside help Goal Completion
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Inspired to perform well by the completion of tasks : Education Preferred Bachelor of Science or better in Computer Systems Management or related field.

Bachelors or better in Computer Information Systems or related field.

Experience Required 5 years: Knowledge and experience with: Office 365/Windows 365, Windows 10, Server 2016/2019, Active directory, group policy, DNS, DHCP, windows certificates services, hyper-V and other virtualization platforms, printer support, Cisco equipment, Dell equipment, and firewalls. 5 years: Network maintenance, switch, router configuration, VOIP telephony, alarm networks, door badge/access equipment. 5 years: Building and maintaining servers that meet CMMC requirements, performing administrative duties and providing customer service on multiple classified and unclassified enclaves.

Supported continuity of operations (COOP) and skilled in multiple system back-up tools (Veritas, Rubrik, Backup exec). Licenses & Certifications Equal Opportunity Employer