Senior Linux Systems Administrator

Senior Linux Systems Administrator

Employment Type: Contract-to-Hire (CTH) or Direct Hire / Full-Time

Work Arrangement: 100% Onsite

Eligible Locations:

Huntsville, AL | Dayton, OH | Albuquerque, NM | Simi Valley, CA | Sunrise, FL | Herndon, VA | Arlington, VA | Germantown, MD | Melbourne, FL

Export Control Requirement: This position is subject to U.S. export-control requirements. Candidates must be either a U.S. Citizen or U.S. Permanent Resident (Green Card holder). No current or future employment sponsorship is available for this position. Please do not apply if you do not meet this requirement.

Position Overview

We are seeking an experienced Senior Linux Systems Administrator to support large-scale Linux infrastructure used by engineering, development, and enterprise technology teams.

This position requires a strong hands-on background administering Linux servers and workstations in complex, security-conscious environments. The selected individual will be responsible for Linux platform administration, endpoint management, security hardening, authentication, automation, virtualization, storage, troubleshooting, and operational support.

This is a senior-level, hands-on technical position suited for someone who has supported enterprise Linux environments at scale and is comfortable working closely with infrastructure, cybersecurity, engineering, and application teams.

Experience within defense, aerospace, U.S. Air Force, DoD, or another highly regulated environment is highly valuable, but is not mandatory.

Key Responsibilities

• Build, configure, administer, patch, monitor, and troubleshoot enterprise Linux servers and workstations.
• Support Linux environments based primarily on Red Hat Enterprise Linux, Oracle Linux, and Ubuntu.
• Manage large populations of Linux endpoints using enterprise administration and orchestration platforms such as Canonical Landscape, Red Hat Satellite, or Foreman.
• Support Ubuntu developer workstation environments, including software deployment, configuration management, patching, repository administration, and policy enforcement.
• Configure and troubleshoot Linux authentication and authorization technologies, including PAM, SSSD, LDAP, Active Directory, Kerberos, sudo, and FreeIPA.
• Implement and support secure authentication methods for Linux desktops and SSH access, including smart cards, PKI, YubiKey, Duo, Okta, or other MFA technologies.
• Apply security controls and system-hardening standards across Linux infrastructure.
• Support environments operating under frameworks such as NIST SP 800-171, CMMC, DISA STIG, and CIS security benchmarks.
• Configure and maintain Linux security technologies including SELinux, AppArmor, auditd, file-integrity monitoring, system logging, and SIEM forwarding.
• Automate infrastructure administration, configuration, deployments, patching, and remediation using Ansible, Bash, Python, Terraform, Puppet, Chef, or similar technologies.
• Administer Linux virtual machines running within VMware vSphere / ESXi / vCenter environments.
• Configure and troubleshoot Linux storage technologies including LVM, NFS, iSCSI, SAN/NAS, multipathing, and enterprise file systems.
• Provide senior-level escalation support for Linux infrastructure, development environments, engineering applications, build systems, and related enterprise services.
• Troubleshoot services such as DNS, DHCP, LDAP, Kerberos, NTP, SSH, and network connectivity.
• Support engineering software and license-management environments, including technologies such as FlexLM/FlexNet where applicable.
• Develop and maintain backup, recovery, system-restoration, and disaster-recovery procedures.
• Diagnose complex system, application, storage, authentication, and performance problems.
• Monitor infrastructure availability and performance using platforms such as Prometheus, Grafana, Zabbix, or comparable monitoring solutions.
• Create technical documentation, operating procedures, configuration standards, security documentation, and troubleshooting guides.
• Partner with cybersecurity, infrastructure, engineering, network, cloud, and application teams to resolve technical and operational issues.

Required Qualifications

• Bachelor’s degree in Computer Science, Information Technology, Cybersecurity, Engineering, or a related discipline, or equivalent combination of education and relevant professional experience.
• Approximately 8 years of IT infrastructure experience, with significant recent experience supporting enterprise Linux environments.
• At least 6 years of hands-on Linux systems administration experience strongly preferred.
• Strong administration experience with Red Hat Enterprise Linux (RHEL), Oracle Linux, and/or Ubuntu.
• Experience managing enterprise Linux servers as well as Linux desktop/workstation environments.
• Experience with Linux fleet-management or centralized administration technologies such as Canonical Landscape, Red Hat Satellite, Foreman, or equivalent tools.
• Strong knowledge of Linux identity and authentication technologies such as PAM, SSSD, LDAP, Active Directory integration, Kerberos, sudo, and SSH.
• Experience implementing or supporting MFA within Linux environments.
• Hands-on experience with Linux security hardening and security-control implementation.
• Experience working with one or more regulated security frameworks such as NIST 800-171, CMMC, DISA STIG, or CIS benchmarks.
• Strong Ansible experience.
• Strong scripting capabilities using Bash and/or Python.
• Working knowledge of VMware vSphere, ESXi, and vCenter.
• Experience supporting Linux storage technologies such as LVM, NFS, iSCSI, SAN, or NAS.
• Strong troubleshooting skills across Linux operating systems, networking, storage, identity, virtualization, security, and application environments.
• Ability to work 100% onsite at one of the designated locations.

Citizenship / Export-Control Requirement

Due to customer, contractual, and export-control requirements associated with this position, candidates must be either:

• U.S. Citizens, or
• U.S. Lawful Permanent Residents / Green Card holders

Candidates must also be able to satisfy any applicable ITAR/EAR or customer-access requirements associated with the work.

A currently active security clearance is not required for this position unless otherwise specified for a particular program. Candidates should be capable of obtaining a U.S. Government security clearance if the assignment later requires one.

Preferred Qualifications

The following experience is beneficial but is not mandatory:

• Aerospace or defense industry experience.
• U.S. Air Force, DoD, military, federal government, or government-contractor environment.
• CMMC Level 2 implementation or remediation experience.
• Direct experience applying DISA STIGs to Linux systems.
• Canonical Landscape administration within a large Ubuntu environment.
• Red Hat Satellite or Foreman administration.
• RHCE, RHCA, LPIC-3, Security , CISSP, or similar certifications.
• Docker, Podman, Kubernetes, or container-platform experience.
• AWS, AWS GovCloud, Azure, Azure Government, or Oracle Cloud Infrastructure experience.
• Infrastructure-as-Code experience using Terraform.
• Linux kernel tuning and advanced performance troubleshooting.
• Internal package repository management and repository mirroring.
• Experience supporting engineering/development environments and software-development toolchains.
• FlexLM/FlexNet or similar software-license management experience.

Ideal Candidate

The strongest candidate will be a senior Linux engineer or administrator who is comfortable owning difficult infrastructure problems from initial diagnosis through resolution. This person should combine strong Linux fundamentals with automation, security, identity management, virtualization, and enterprise troubleshooting experience.

The position requires someone who can work effectively in a highly technical onsite environment and communicate clearly with infrastructure, cybersecurity, engineering, and business stakeholders.

For LinkedIn Recruiter, I would divide your sourcing criteria into three levels. This is important because requiring every technology in the original posting—Landscape Oracle Linux RHEL Ubuntu CMMC MFA VMware storage cloud, etc.—will eliminate many otherwise excellent candidates.

Mandatory sourcing skills

These are the skills I would actually use as your core filters:

• Linux Systems Administration
• Linux Administration
• Red Hat Enterprise Linux / RHEL
• Ubuntu
• Oracle Linux
• Ansible
• Bash
• Python
• PAM
• SSSD
• LDAP / Active Directory integration
• Linux Security / Linux Hardening
• VMware / vSphere / ESXi
• NFS / iSCSI / LVM / SAN
• 6 years Linux administration
• U.S. Citizen OR Green Card
• Local/commutable to one of the onsite locations