Information Systems Security Engineer / ISSE (HPC) with Security Clearance

AMERICAN SYSTEMS, a 100% employee-owned federal contractor, is seeking a highly experienced Information Systems Security Engineer (ISSE) to support RHEL and Windows systems in a High Performance Computing (HPC) environment in Arlington, VA. This role includes a $10,000 sign-on bonus in addition to a generous compensation package. Responsibilities As an Information Systems Security Engineer (ISSE) at AMERICAN SYSTEMS, you will: * Design and implement enterprise-level security architectures for RHEL systems in a High Performance Computing (HPC) SAP environment * Apply JSIG requirements to system authorization, control implementation, and documentation * Manually develop RMF/JSIG authorization artifacts, including SSPs, control narratives, POA&Ms, and supporting evidence * Perform hands-on security assessments on Linux and Windows systems, including command-line audits, compliance scans, log review, and control validation * Analyze scan results, identify security gaps, and support remediation planning and execution * Validate and implement host-based firewall and security configurations in coordination with system administrators * Manage and track POA&Ms through mitigation, remediation, or risk acceptance * Ensure system compliance through continuous monitoring of controls, procedures, and documentation * Identify security deficiencies and provide actionable remediation recommendations * Support system recovery and security oversight following outages or incidents * Participate in change management activities, assessing security impacts to SAP systems * Support security investigations, incident response, and remediation activities * Collaborate with engineering teams to integrate security requirements into system design and production releases Qualifications * Active Top Secret/SCI with SAP eligibility * Bachelor's degree in a STEM discipline with 11-12 years of relevant experience, or * Master's degree with 8-10 years of relevant experience * Minimum 5 years of experience designing and implementing enterprise-scale security solutions with hands-on security assessment experience across Linux systems, including command-line validation * DoD 8140 IAT Level III-equivalent certification (e.g., SecurityX, CISSP, CCNP Security, CISA, GCED, GCIH, or CCSP) * Strong background in RMF, ICD 503, NIST SP 800-53, DCID 6/3, or current DoD authorization practices * Working knowledge of the JSIG and its application to RMF authorization * Proven experience authoring RMF/JSIG artifacts by hand, without reliance on automated RMF tools (eMASS, Xacta, etc.) * Experience supporting security tools such as Splunk Enterprise, HBSS, McAfee ePO, ENS, and DLP * Demonstrated security engineering experience across Linux, Windows, Cisco platforms, databases (SQL or Oracle), and virtualized environments AMS1 Pay Transparency Statement AMERICAN SYSTEMS is committed to pay transparency for our applicants and employee-owners. The salary range for this position is USD $165,000.00/Yr. - USD $200,000/Yr. Actual compensation will be determined based on several factors permitted by law. AMERICAN SYSTEMS provides for the welfare of its employees and their dependents through a comprehensive benefits program by offering healthcare benefits, paid leave, retirement plans, insurance programs, and education and training assistance. EEO Statement EEO Race/Sex/Disability Status/Veteran Status