Information System Security Engineer

Job Description: We are seeking an Information System Security Engineer (ISSE) to support a critical national security program. The ISSE serves as a bridge between high-level security requirements and the technical implementation of those policies in Government (DoD, Intelligence Community) information systems. You will collaborate with the Information System Security Manager (ISSM), Program Manager, and engineering teams to guide the system through Assessment and Authorization (A&A), support ICD-503 RMF compliance, and maintain accreditation. Core Responsibilities: Implement cybersecurity policies and technical controls in line with DoD/IC compliance standards Provide guidance and oversight to development teams working toward system accreditation Support and author A&A documentation including: Security CONOPS System Security Plans (SSP) Security Control Assessments (SCA) Incident Response Plans (IRP) Configuration and Contingency Plans POA&Ms, Risk Management Plans, and audit artifacts Manage continuous monitoring and security auditing processes Interface with scanning and compliance tools (e.g., NESSUS, NMAP, Rapid7) Act as a cybersecurity SME across a broad Linux-based enterprise system Advise on and evaluate security architectures and controls Cross-train and support across other infrastructure components Required Skills: Deep expertise with ICD-503 C&A process and related documentation Experience in security engineering across: Systems and network architecture Firewalls, DMZs, encryption Software/hardware lifecycle security Understanding of RMF and frameworks such as: NIST SP 800-37 CNSS publications Hands-on experience with security compliance and monitoring tools: NESSUS, NMAP, WebInspect, AppDetective, SNOW Security certifications: Security+ or CISSP (required) Experience supporting A&A testing and evaluations Ability to communicate security practices clearly with development teams Analyze and validate security designs for compliance Desired Skills: Proficiency with Red Hat Linux/Unix and Windows environments 5+ years as a Linux system admin/engineer Experience with: Puppet, Ansible, Foreman Git, GitLab, SVN PKI, SSH, SSSD, HTTPD Amazon Web Services or other cloud technologies VMware (VSAN, vCenter), Veeam backup integration Enterprise tools (Grafana, Jira, Elastic Stack, FreeIPA) SAN Storage (preferably IBM GPFS) Familiarity with Cisco networking (CCNA/CCNA Security) and storage bootstrapping (e.g., HPE, iLO) Experience with audit logging from heterogeneous systems Strong script writing skills for system automation Experience with relational databases such as Oracle, MySQL Excellent written communication-able to convey technical and executive-level insights Education & Experience: Bachelor's Degree in Computer Science, IT, or related field 10+ years of professional experience in cybersecurity/system administration US Citizenship required Active TS/SCI clearance required, with ability to obtain CI Polygraph