Senior Systems Administrator

Job Description:

Are you passionate about solving complex technical challenges in support of national security? Leidos is seeking a Senior Systems Administrator to join our high-performing team on the Chinook Program, supporting our Intelligence Community customer. In this mission-critical role, you’ll be at the forefront of maintaining and enhancing the application ensuring the reliability, security, and performance of systems that directly enable intelligence operations.

As a trusted technical expert, you’ll work alongside talented engineers, cybersecurity professionals, and customer stakeholders to deliver innovative solutions, optimize enterprise infrastructure, and keep mission-essential capabilities operating at peak performance. If you thrive in a fast-paced, collaborative environment where your expertise has a tangible impact, this is an opportunity to contribute to work that truly matters.

Position is performed at the customer site in St. Louis, MO.

Clearance Level Required:

Active Top Secret/SCI with the ability to successfully pass a Polygraph examination.

Primary Responsibilities:

• Administer, maintain, and support the application with the customer enterprise.
• Perform installation, configuration, patching, upgrades, and lifecycle management of Windows and Linux servers.
• Monitor system health, performance, and availability using enterprise monitoring tools.
• Troubleshoot complex hardware, software, operating system, and application issues.
• Support deployment activities across development, test, staging, and production environments.
• Coordinate scheduled maintenance windows and execute system upgrades with minimal operational impact.
• Develop and maintain automation scripts using PowerShell, Bash, or Python to improve operational efficiency.
• Perform backup, recovery, and disaster recovery operations.
• Support accreditation activities and ensure compliance with customer, DoD, RMF, DISA STIG, and security requirements.
• Manage user accounts, permissions, and Active Directory integrations.
• Collaborate with security teams to remediate vulnerabilities and maintain compliance.
• Support incident response, root cause analysis, and corrective action implementation.
• Document system configurations, standard operating procedures, and technical documentation.
• Participate in on-call rotation and provide after-hour support when required.
• Interface directly with customer to address operational tasking and mission requirements.

Basic Qualifications:

• US citizenship is required per contract.
• Bachelor’s degree in Information Technology, Computer Science, Engineering, or related field and 8-12 years of prior relevant experience or Master’s with 6-10 years of prior relevant experience.
• 8+ years of enterprise systems administration experience.
• Experience supporting mission-critical DoD or Intelligence Community environments.
• Strong administration experience with:
  • Microsoft Windows Server
  • Red Hat Enterprise Linux (RHEL)
  • VMware vSphere
  • Active Directory
  • DNS/DHCP
  • Group Policy
• Experience with scripting and automation using PowerShell, Bash, or Python.
• Experience implementing and maintaining STIG compliance.
• Knowledge of RMF security controls and vulnerability remediation.
• Strong troubleshooting and analytical skills.
• Must have a Security+ CE or higher DoD 8570/8140 certification

Preferred Qualifications:

• Experience supporting customer mission systems.
• Experience supporting GEOINT applications.
• Experience with:
  • Ansible
  • VMware vCenter
  • SCCM/MECM
  • Splunk
  • Elastic Stack
  • Git
  • ServiceNow
• Red Hat Certified Systems Administrator (RHCSA)
• Microsoft Certified: Windows Server Hybrid Administrator Associate
• ITIL Foundation Certification

If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo — because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 — and moving faster than anyone else dares.

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