cFocus Software seeks a Linux System Administrator to join our program supporting the National Institutes of Health (NIH). This position is fully remote. This position requires a Public Trust or the ability to obtain a public trust clearance. Qualifications:Public Trust Clearance B.S. Computer Science, Information Technology, or a related field 5+ years administering enterprise Linux environments. Experience with enterprise infrastructure engineering, automation, virtualization, cloud technologies, and cybersecurity. Experience supporting federal or highly regulated environments preferred RHCSA, RHCE, CompTIA Security+, Linux+, GCUX, or CISSP (preferred) Duties:Administer, configure, maintain, and optimize enterprise Linux operating systems including Red Hat Enterprise Linux (RHEL), Rocky Linux, Ubuntu, and Oracle Linux. Support Security Architecture engineering activities by designing, implementing, and maintaining secure Linux server architectures. Implement Zero Trust Architecture principles including least privilege, identity-based access controls, micro-segmentation, and continuous verification. Deploy, configure, and maintain enterprise authentication services (LDAP, Active Directory integration, Kerberos, SSSD, MFA). Perform operating system hardening using DISA STIGs, CIS Benchmarks, and NIST guidance. Manage enterprise patching, software lifecycle management, kernel updates, and configuration management. Develop automation using Bash, Python, Ansible, or similar tools to improve operational efficiency. Support virtualization, cloud-hosted Linux systems, containers, and hybrid infrastructure. Participate in architecture reviews, system engineering efforts, change management, disaster recovery, and system documentation. Collaborate with Security Architects, Network Engineers, ISSOs, Vulnerability Analysts, and application teams to maintain secure enterprise infrastructure.