Systems Administrator - Senior

Location: Chantilly, VA | Full-Time

About the Role

We are seeking an experienced Senior Systems Administrator to support mission-critical enterprise applications, infrastructure, and platform services within a secure government environment. The ideal candidate will maintain, troubleshoot, and enhance Windows and UNIX/Linux-based systems while ensuring high availability, security, and operational efficiency.

Responsibilities

• Administer and maintain Windows and UNIX/Linux server environments.
• Install, configure, and support operating systems and enterprise applications.
• Monitor system performance, availability, and overall infrastructure health.
• Troubleshoot hardware, software, storage, network, and operating system issues.
• Provide Tier 1 and Tier 2 technical support for enterprise systems.
• Manage user accounts, permissions, and system security.
• Support server, storage, networking, and virtual infrastructure.
• Configure and maintain enterprise network components.
• Perform system upgrades, patch management, and operating system enhancements.
• Analyze system performance and conduct capacity planning.
• Integrate new technologies into existing enterprise environments.
• Support DevSecOps processes and infrastructure automation.
• Collaborate with engineering teams on system architecture and deployment activities.
• Maintain documentation, procedures, and technical runbooks.
• Participate in training, knowledge sharing, and continuous process improvement.
• Escalate critical incidents and communicate status to stakeholders.

Requirements

• Active Top Secret/SCI Security Clearance with CI Polygraph.
• DoD 8570 IAT/IAM Level II Certification.
• Experience supporting enterprise Windows and UNIX/Linux environments.
• Strong understanding of enterprise infrastructure and systems administration.
• Experience working within DevSecOps environments.
• Knowledge of Oracle and/or CentOS architecture.
• Experience with cloud infrastructure and Platform as a Service (PaaS).
• Familiarity with OpenShift environments.
• Working knowledge of Java-based applications.
• Experience using GitLab, Bitbucket, Jenkins, Nexus, Jira, and Confluence.
• Strong troubleshooting and analytical skills.
• Ability to prioritize multiple tasks in a fast-paced environment.
• Excellent verbal and written communication skills.

Preferred Qualifications

• Bachelor's Degree in Information Technology, Computer Science, Information Systems, or a related discipline.
• 10+ years of enterprise systems administration experience.
• Experience supporting Intelligence Community or Department of Defense programs.
• Strong understanding of enterprise architecture and secure infrastructure.
• Experience with risk management and compliance.
• Knowledge of mission-critical application support.

Skills

Operating Systems

• Windows Server
• UNIX
• Linux
• CentOS

Cloud & Infrastructure

• Cloud Platforms
• OpenShift
• Platform as a Service (PaaS)
• Enterprise Infrastructure
• Server Administration
• Storage Administration
• Network Administration

DevSecOps Tools

• GitLab
• Bitbucket
• Jenkins
• Nexus
• Jira
• Confluence

Technologies

• Oracle
• Java
• System Monitoring
• Capacity Planning
• Infrastructure Automation
• Network Troubleshooting

Soft Skills

• Strong analytical and problem-solving abilities.
• Excellent communication and interpersonal skills.
• Ability to work independently and within cross-functional teams.
• Strong organizational and time-management skills.
• Detail-oriented with excellent documentation practices.
• Adaptable and able to manage multiple priorities.
• Continuous learning mindset.

Education & Experience

• High School Diploma/GED with 16+ years of relevant experience, or
• Associate Degree with 14+ years of relevant experience, or
• Bachelor's Degree with 12+ years of relevant experience, or
• Master's Degree with 10+ years of relevant experience.

Ideal Candidate

The ideal candidate is a senior systems administrator with extensive experience managing secure enterprise Windows and Linux environments, supporting DevSecOps operations, and maintaining mission-critical infrastructure. Candidates should possess an active TS/SCI clearance with CI Polygraph, strong troubleshooting expertise, and experience working within highly secure government or defense environments.