Senior Linux Systems Administrator

The

Senior Linux Systems Administrator is responsible for designing, deploying, securing, automating, and maintaining enterprise Linux server infrastructure and developer workstation fleets across on‑premises and multi‑cloud environments.

This role serves as the subject matter expert for enterprise Linux distributions Oracle Linux, Red Hat Enterprise Linux, Ubuntu
, configuration management, and centralized orchestration. A primary focus includes managing and scaling Canonical Landscape to administer hundreds of Ubuntu developer desktops within a strict CMMC 2.0 Level 2 / NIST SP 800-171 compliant environment. The ideal candidate brings deep expertise in Linux PAM architecture, enterprise MFA integrations, infrastructure‑as‑code automation, and defense‑in‑depth security hardening.

• Enterprise Linux Server Administration:
  Design, build, configure, and maintain mission‑critical Linux servers across on‑prem (VMware vSphere) and cloud environments (OCI, AWS, Azure), supporting engineering workloads, database platforms, and custom development pipelines.
• Developer Fleet Management:
  Architect, deploy, and administer Canonical Landscape to manage configuration profiles, package repositories, compliance policies, and automated patch management for hundreds of Ubuntu developer endpoints.
• Identity & Access Management (MFA/PAM):
  Implement and enforce robust authentication and authorization frameworks, including smart card/FIPS‑compliant MFA at desktop and SSH login, PAM module engineering, SSSD/FreeIPA integration, Active Directory/LDAP bridging, and centralized sudoers delegation.
• CMMC L2 & Security Compliance:
  Harden Linux servers and workstations to NIST SP 800‑171, DISA STIG, and CIS Level 2 benchmarks. Implement SELinux/App Armor enforcement, auditd daemon logging, file integrity monitoring (FIM), and SIEM log forwarding.
• Automation & Configuration Management:
  Develop and maintain Infrastructure‑as‑Code (IaC) and configuration baselines using Ansible, Terraform, Puppet/Chef, and advanced Bash/Python scripting.
• Storage & Virtualization:
  Configure and troubleshoot enterprise SAN/NAS storage, iSCSI/NFS mounts, multipathing, LVM volumes, and VMware ESXi/vCenter virtualization for Linux guests.
• Engineering Tools & Service Desk Escalation:
  Serve as Tier 3 escalation support for engineering applications, tool chains, build environments, license managers (FlexLM), and core network/directory services (DNS, DHCP, LDAP, Kerberos, NTP).
• High Availability & Disaster Recovery:
  Design robust backup and recovery workflows, test system failover procedures, monitor system health/telemetry (Prometheus, Grafana, Zabbix), and resolve complex performance bottlenecks.

• Education:
  
  Bachelor’s degree in Computer Science, Information Technology, Cybersecurity, or equivalent combination of education, technical training, and experience.
• Experience:
  
  Minimum of 8–12 years of total IT infrastructure experience, with at least 6+ years focused on enterprise Linux systems administration.
• Distribution Mastery:
  Deep, hands‑on administration of Oracle Linux (UEK), Red Hat Enterprise Linux (RHEL), and Ubuntu Server/Desktop.
• Fleet Management:
  Proven experience managing Linux endpoints at scale using Canonical Landscape, Red Hat Satellite, or Foreman.
• Authentication & MFA:
  Demonstrated experience implementing Linux desktop and SSH Multi‑Factor Authentication (Yubi Key, PKI/Smartcard, Duo, or Okta PAM integration).
• Compliance & Hardening:
  Direct experience hardening Linux environments to NIST SP 800‑171, CMMC Level 2, or DISA STIG requirements.
• Automation:
  Strong proficiency in Ansible and scripting with Bash or Python.
• Virtualization & Storage:
  Solid experience with VMware vSphere/ESXi and enterprise storage management (LVM, NFS, iSCSI, SAN).
• Security Clearance / Export Control:
  Must be a U.S. Person (U.S. Citizen or Lawful Permanent Resident) due to compliance with ITAR/EAR regulations; ability to obtain and maintain a DoD Security Clearance if required.

• Active industry certifications: RHCE / RHCA, LPIC‑3, CompTIA Security+, or…