Systems Administrator (All Levels) - TS/SCI w/ FSP

Job#: 3026290

Job Description:
Systems Administrator (All Levels) - TS/SCI w/ Full Scope Polygraph (FSP)

Location: Linthicum, MD / Annapolis Junction, MD

Work Model: 100% On-Site (classified environment; not remote)

Clearance: Active TS/SCI with Full Scope Polygraph (FSP) required (must be active/current)

Employment Type: Contract

We're seeking Systems Administrators (multiple levels) to support mission-critical classified environments for a large DoD integrator. You'll help design, deploy, secure, sustain, and troubleshoot Windows and/or Linux systems, often in virtualized (VMware) on-prem environments. Work includes partnering closely with network, security, software, and program teams to maintain high availability and compliance.

Leveling note: This posting is intended to source multiple skill levels (Junior through Principal/SME). Final level/title aligns to experience and technical depth.
What You'll Do (Responsibilities may vary by level)

Core Systems Administration (Windows and/or Linux):

• Administer and sustain Windows Server and/or Linux (RHEL) systems in a classified environment.
• Install, configure, harden, patch, and troubleshoot servers/workstations; monitor performance and reliability; resolve incidents and implement preventive fixes.
• Manage user and computer accounts, permissions, and access controls (e.g., AD, groups, file permissions, security ACLs).
• Support backup/recovery, storage/file systems, capacity planning, and routine maintenance (disk space, log maintenance, etc.).

Virtualization / Infrastructure (as applicable):

• Administer VMware vSphere / ESXi / vCenter (provisioning, lifecycle, configuration, monitoring, troubleshooting).
• Support physical/virtual server environments and coordinate with adjacent infrastructure teams.

Security & Compliance (classified/RMF environments):

• Follow strict Information Systems security procedures; maintain audit/logging and support security documentation as required.
• Implement and maintain DISA STIG configurations; coordinate remediation and document risk/mitigation items (e.g., POA&M support where applicable).
• Support system hardening and ongoing compliance aligned to RMF practices.

Operations, Documentation, and Customer Support:

• Coordinate with network/software/system engineers, ISSM/ISSO partners, desktop teams, project managers, and end users to keep systems operating smoothly.
• Document procedures/SOPs, changes, and troubleshooting steps; communicate status to stakeholders.
• Evaluate and work with vendors on solutions, components, and issue resolution.

Optional Specialized Responsibilities (based on need):

• Splunk administration (indexers/search heads/deployment servers, dashboards, SPL queries, onboarding data sources).
• Endpoint security tooling / monitoring (e.g., HBSS/Trellix), vulnerability scanning workflows, or automation/scripting.

Required Qualifications (Baseline)

• Active TS/SCI with Full Scope Polygraph (FSP).
• Hands-on Systems Administration experience in Windows and/or Linux environments supporting production users/systems.
• Experience with at least one of the following, depending on alignment:
  • Windows Server, Active Directory, Group Policy
  • RHEL/Linux administration
  • VMware (vSphere/ESXi/vCenter)
• Comfort working on-site in a classified environment (no remote).
• DoD 8570 / 8140-aligned baseline certification (commonly Security+ CE or equivalent), if required by the program.

Preferred Qualifications (Add-ons that help you source wider skill mixes)

• Experience operating in environments requiring STIG compliance and security documentation support.
• Knowledge of basic networking concepts (subnets, routing, VLANs) and troubleshooting cross-team issues.
• Storage/SAN familiarity, system imaging/provisioning, and hardware install/refresh experience.
• Scripting/automation (PowerShell, Bash, Python) to reduce toil and standardize builds.
• Monitoring/logging tools exposure (Splunk, SolarWinds, etc.).

Apex Systems is a world-class IT services company that serves thousands of clients across the globe. When you join Apex, you become part of a team that values innovation, collaboration, and continuous learning. We offer quality career resources, training, certifications, development opportunities, and a comprehensive benefits package. Our commitment to excellence is reflected in many awards, including ClearlyRated's Best of Staffing in Talent Satisfaction in the United States and Great Place to Work in the United Kingdom and Mexico. Apex uses a virtual recruiter as part of the application process. Click for more details.

Apex Benefits Overview: Apex offers a range of supplemental benefits, including medical, dental, vision, life, disability, and other insurance plans that offer an optional layer of financial protection. We offer an ESPP (employee stock purchase program) and a 401K program which allows you to contribute typically within 30 days of starting, with a company match after 12 months of tenure. Apex also offers a HSA (Health Savings Account on the HDHP plan), a SupportLinc Employee Assistance Program (EAP) with up to 8 free counseling sessions, a corporate discount savings program and other discounts. In terms of professional development, Apex hosts an on-demand training program, provides access to certification prep and a library of technical and leadership courses/books/seminars once you have 6+ months of tenure, and certification discounts and other perks to associations that include CompTIA and IIBA. Apex has a dedicated customer service team for our Consultants that can address questions around benefits and other resources, as well as a certified Career Coach. You can access a full list of our benefits, programs, support teams and resources within our 'Welcome Packet' as well, which an Apex team member can provide.