Information System Security Engineer (ISSE)

• Design, review, and implement cybersecurity architecture and engineering solutions supporting enterprise and mission systems.
• Integrate security requirements into system design, development, testing, implementation, and sustainment activities.
• Support and lead RMF activities throughout the authorization lifecycle, including categorization, control selection, implementation, assessment, authorization, and continuous monitoring.
• Develop, review, and maintain RMF documentation including System Security Plans (SSPs), Security Control Traceability Matrices (SCTMs), Security Assessment Reports (SARs), and Plans of Action & Milestones (POA&Ms).
• Evaluate system changes, upgrades, and new capabilities to determine cybersecurity impacts and authorization requirements.
• Validate implementation of NIST SP 800-53 security controls and DISA Security Technical Implementation Guides (STIGs).
• Conduct cybersecurity architecture reviews, security engineering analyses, and technical risk assessments.
• Analyze ACAS, Tenable, Nessus, and SCAP assessment results and coordinate remediation efforts with system administrators and engineering teams.
• Develop and implement continuous monitoring strategies to maintain cybersecurity compliance and authorization status.
• Participate in Configuration Control Boards (CCBs), Technical Review Boards (TRBs), and engineering working groups.
• Provide technical guidance and cybersecurity recommendations to system owners, ISSOs, ISSMs, and senior leadership.
• Support cybersecurity inspections, Security Control Assessor (SCA) assessments, and Command Cyber Readiness Inspections.
• Evaluate interconnections, data flows, and system architectures to identify security risks and recommend mitigations.
• Track vulnerability remediation efforts and maintain POA&M activities to meet organizational and regulatory requirements.
• Support implementation and adoption of Zero Trust principles and cybersecurity modernization initiatives.
• Prepare technical reports, executive summaries, and briefing materials for leadership decision-making.

• Active Secret clearance with the ability to obtain and maintain a Top-Secret clearance.
• Must meet DoD 8140 qualification requirements for DCWF 652 Security Architect Intermediate (Primary)
• Bachelors Degree in Computer Science, Cybersecurity, Data Science, Information Systems, Information Technology, or Software Engineering // OR // GMON, SecurityX, CCSP, CISSO, Cloud+, CSSLP, FITSP-D, GCSA, or GSEC.
• DCWF 461 Systems Security Analyst Intermediate (Secondary)
• Bachelors Degree in Computer Science, Cybersecurity, Data Science, Information Systems, Information Technology, or Software Engineering // OR // CCSP, Cloud+, GICSP, GISF, GSEC, or Security+.
• Six (6) years of experience supporting cybersecurity, information assurance, systems engineering, or RMF-related activities.
• Experience supporting DoD Assessment and Authorization (A&A) or RMF processes.
• Experience with eMASS and maintenance of RMF authorization packages.
• Experience implementing and assessing NIST SP 800-53 security controls.
• Experience with ACAS, Tenable Security Center, Nessus, SCAP, and vulnerability management processes.
• Working knowledge of Windows, Linux, networking, virtualization, and enterprise information systems.
• Strong communication skills with the ability to engage both technical and non-technical stakeholders., * Active Top Secret clearance with SCI eligibility.
• CISSP certification.
• CISSP-ISSEP, CCSP, CGRC, SecurityX (formerly CASP+), or CSSLP certification.
• Experience supporting Combatant Command, Navy, or Joint operational environments.
• Experience with Zero Trust Architecture implementation.
• Knowledge of Cross Domain Solutions (CDS) and Commercial Solutions for Classified (CSfC).
• Experience with cloud security technologies and hybrid cloud environments.
• Experience conducting cybersecurity architecture reviews and secure design assessments.
• Experience using JIRA, Confluence, ServiceNow, or similar collaboration and workflow platforms.
• Experience supporting Security Control Assessor reviews and ATO renewals.

• Working conditions are normal for an office environment.
• Fast paced, deadline-oriented environment.
• May require periods of non-traditional working hours including consecutive nights or weekends.

Working at SOSi:

All interested individuals will receive consideration and will not be discriminated against for any reason.

Founded in 1989 and headquartered in Reston, Virginia, SOSi is a private defense and government solutions business specializing in advanced technology systems and mission support. Its capabilities include data science, software development, network engineering, intelligence, surveillance, and reconnaissance (ISR), and logistics.