Linux System Administrator

Delaware Nation Industries is seeking a Senior Linux System Administrator to provide advanced systems administration and engineering support for the Air Force Joint Worldwide Intelligence Communications System/Joint Interoperability Test and Services mission. This role maintains secure, resilient, and highly available Linux infrastructure across classified and unclassified environments supporting mission-critical operations. The Senior Linux System Administrator serves as a technical authority for Linux platforms, virtualization, automation, system security, performance, and lifecycle management.

Responsibilities

• Administer, engineer, optimize, and maintain enterprise Linux systems and services across multiple security levels and operational environments
• Install, configure, harden, patch, upgrade, and decommission Linux operating systems, applications, services, and supporting infrastructure
• Support Red Hat Enterprise Linux and other approved Linux distributions, including system services, package management, storage, networking, authentication, logging, and performance tuning
• Design and implement repeatable procedures for system builds, provisioning, configuration management, patching, backup, recovery, restoration, and lifecycle operations
• Analyze complex system, application, hardware, virtualization, storage, and network problems; conduct root-cause analysis and implement durable corrective actions
• Monitor system availability, resource utilization, capacity, performance, and security posture; identify risks and recommend improvements before they affect mission operations
• Administer and troubleshoot VMware or comparable virtualized infrastructure, including virtual machines, images, templates, virtual networking, and storage dependencies
• Develop and maintain scripts and automation using Bash, Python, Ansible, Puppet, or comparable tools to improve consistency, reduce manual effort, and support troubleshooting
• Support DevSecOps practices, source-code or configuration repositories, automated workflows, and controlled deployment processes when applicable to the environment
• Apply DISA STIGs, security baselines, vulnerability-remediation procedures, and other DoD cybersecurity requirements to Linux systems and applications
• Execute or support ACAS/Nessus scans, vulnerability analysis, remediation, validation, and compliance reporting
• Maintain secure system access, including accounts, roles, privileges, SSH, authentication services, certificates, keys, and least-privilege controls
• Support SAN/NAS storage, NFS, iSCSI, file systems, backup infrastructure, and data-transfer services as assigned
• Support authorized electronic and manual data transfers between network environments and troubleshoot transfer failures, integrity issues, and related operational problems
• Participate in system integration, testing, acceptance, change control, technical interchange meetings, exercises, and mission-readiness activities
• Produce and maintain system documentation, architecture diagrams, standard operating procedures, configuration records, plans of action and milestones, and technical reports
• Provide technical leadership, mentoring, knowledge transfer, and cross-training to Mid-level administrators and other team members
• Coordinate with cybersecurity, network, Windows, application, database, service desk, and Government teams to resolve escalated incidents and maintain continuity of operations
• Participate in scheduled maintenance, planned outages, incident response, and after-hours or on-call support as required by the contract

Requirements

• Active DoD TS/SCI security clearance
• At least six (6) years of professional Unix/Linux systems administration experience
• DoD 8570/8140-compliant IAT III certification, such as CISSP, CASP+ or another current DoD-approved equivalent
• Demonstrated experience administering enterprise Linux systems in a DoD, intelligence, classified, or similarly regulated environment
• Strong knowledge of Linux system architecture, networking, storage, system services, access control, logging, troubleshooting, and performance tuning
• Experience with system backup and recovery, software and patch management, security hardening, vulnerability remediation, and configuration control
• Experience with virtualization technologies, preferably VMware vSphere and related management components
• Proficiency with shell scripting and demonstrated ability to automate or streamline system administration tasks
• Experience diagnosing complex technical issues, performing root-cause analysis, and communicating solutions to technical and nontechnical stakeholders
• Strong written and verbal communication skills and the ability to work independently, lead technical efforts, and collaborate across functional teams

Preferred Qualifications

• Experience supporting Air Force, JWAC, JITS, Joint, intelligence, or other DoD mission environments
• Experience with Red Hat Enterprise Linux 7/8/9 or successor supported releases, CentOS, Scientific Linux, Debian, or comparable distributions
• Experience with Puppet Enterprise, Ansible, CloudBolt, Git, Docker, or comparable automation and DevSecOps technologies
• Experience supporting multi-level security, cross-domain solutions, classified networks, data-transfer systems, or mission-essential communications environments
• Experience with ACAS/Nessus, HBSS/endpoint security tools, STIG Viewer, vulnerability-management platforms, or comparable DoD cybersecurity tools
• Experience with SAN/NAS technologies, NFS, iSCSI, RAID, LVM, XFS, ext4, ZFS, or other enterprise file systems
• Experience with DNS, DHCP, NTP, LDAP/Active Directory integration, RADIUS, PKI, certificates, SSH, TCP/IP, and firewall-related troubleshooting
• Experience with monitoring, logging, configuration-management, ticketing, and IT service-management platforms
• Bachelor's degree in information technology, computer science, cybersecurity, engineering, or a related field; equivalent experience may be considered
• Linux, VMware, automation, security, or other relevant industry certifications