Senior Information Security Engineer — RMF/NIST Expert

VTG Defense; McLean (VA); On-site; USD 120,000 - 180,000; Full time

Job summary

VTG Defense is seeking an Information Systems Security Engineer (ISSE) to design, implement, and maintain security controls across enterprise systems and networks. This role supports RMF and NIST 800-53 compliance while enabling mission-critical operations.

The ISSE will work with ISSOs, system administrators, and developers to remediate vulnerabilities, perform risk analyses, and ensure robust security architecture. A TS/SCI with Polygraph is required.

Qualifications

• Active TS/SCI with Polygraph required.
• 5+ years in information security, focused on system security engineering.
• Hands-on RMF experience and NIST 800-53 controls.
• Experience with A&A documentation (SSP, POA&M, ATO packages).
• Knowledge of Windows and Linux security.
• Familiarity with vulnerability scanning tools (ACAS, Nessus, or similar).
• Experience with security tools (SIEM, firewalls, endpoint protection).
• Understanding of encryption, identity management, and access control mechanisms.

Responsibilities

• Design, implement, and maintain security controls for information systems and networks.
• Support RMF lifecycle: system categorization, control selection, implementation, assessment, and authorization.
• Conduct security assessments, vulnerability scans, and risk analysis.
• Develop and maintain system security documentation (SSP, POA&M, SAR, etc.).
• Ensure systems comply with NIST, RMF, and organizational security policies.
• Collaborate with ISSOs, system administrators, and developers to remediate vulnerabilities.
• Support continuous monitoring and incident response activities.
• Implement and manage security tools (SIEM, IDS/IPS, endpoint protection).
• Provide technical guidance on secure system architecture and design.
• Stay current on emerging threats, vulnerabilities, and security technologies.

Skills

RMF lifecycle

NIST 800-53

Vulnerability scanning

SIEM

IDS/IPS

Endpoint protection

Access control

Security architecture

Education

Bachelor's degree in Cybersecurity or related field

Tools

ACAS

Nessus

SIEM

Firewall

Job description

VTG Defense is seeking an Information Systems Security Engineer (ISSE) to design, implement, and maintain security controls across enterprise systems and networks. This role supports RMF and NIST 800-53 compliance while enabling mission-critical operations.

The ISSE will work with ISSOs, system administrators, and developers to remediate vulnerabilities, perform risk analyses, and ensure robust security architecture. A TS/SCI with Polygraph is required.