Responsibilities:Perform hands-on security engineering, configuration, troubleshooting, and hardening of Red Hat Enterprise Linux (RHEL) systemsImplement, validate, and maintain DISA STIG compliance, including executing SCAP scans, analyzing findings, and remediating security vulnerabilitiesTroubleshoot Linux security configurations involving SELinux, SSH, permissions, authentication, system services, and networkingLead and support Assessment and Authorization (A&A) activities to achieve and maintain Authorization to Operate (ATO) under the Risk Management Framework (RMF)Develop and maintain security documentation, including System Security Plans (SSPs), Security Assessment Reports (SARs), Security Control Traceability Matrices (SCTMs), and Plans of Action and Milestones (POA&Ms)Conduct security assessments and continuous monitoring activities aligned with ICD 503, NIST 800-53, CNSSI, and applicable DoD requirementsCollaborate with systems, network, software, and DevOps engineers to integrate security requirements throughout the System Development Life Cycle (SDLC)Evaluate system architectures, infrastructure changes, and software configurations to identify security risks and recommend mitigationsDevelop Bash or Python scripts to automate security compliance, vulnerability assessments, and routine administrative tasks. Qualifications: Required:Required5+ years of combined experience in cybersecurity engineering, information assurance, Linux systems administration, or related technical disciplinesMinimum 2 years of hands-on Linux administration experience, preferably with RHEL 8/9Practical Linux command-line proficiency, including filesystem management, permissions, user administration, package management (DNF/YUM), systemd services, log analysis, SSH, and basic network troubleshootingExperience implementing Linux DISA STIGs, executing SCAP scans, and performing vulnerability remediationWorking knowledge of Linux security technologies, including SELinux, firewalld, authentication, and access controlsExperience with Bash scripting and/or Python for system administration or security automationStrong understanding of RMF, ICD 503, NIST 800-53, and the ATO lifecycleDoD 8570/8140 IAT Level II certification (Security+ CE, CySA+, SSCP, or equivalent applicable certification)Bachelor's degree in a technical discipline or equivalent relevant experienceActive Top Secret clearance with SCI eligibility.