Senior Information Systems Security Engineer (ISSE)

Location: Arlington, VA

Department: Cyber Security Services

Reports To: Management

FLSA Status: Full Time/Non-exempt

Apavo is at the forefront of cybersecurity, providing services to military, defense, and critical infrastructure industries. Joining the Apavo team means becoming part of a company rooted in the principles of quality, and communication. We value positive, candid interactions and the belief that everyone has valuable contributions to make. Apavo stands out for its commitment to a work-life balance and fostering a growth mindset among all team members. If you are looking to make a meaningful impact in the cybersecurity world while growing professionally in a supportive environment, Apavo is the place for you.

Job Purpose:

The Senior Information Systems Security Engineer (ISSE) provides expert-level technical security engineering support throughout the system lifecycle, ensuring information systems are designed, developed, and maintained in accordance with applicable security requirements. This role works closely with ISSOs, system owners, and engineering teams to integrate security controls into system design, lead security engineering efforts on complex initiatives, and support the Assessment and Authorization (A&A) process.

Duties & Responsibilities:

The Senior ISSE responsibilities include, but are not limited to:

• Provide senior-level security engineering support across the system development lifecycle, from requirements definition through sustainment
• Apply advanced security engineering principles to integrate controls into system design, architecture, and configuration
• Lead and support the Risk Management Framework (RMF) process, including development and review of security artifacts (SSP, SAR, POA&M, etc.)
• Conduct security control assessments and lead remediation strategies for identified vulnerabilities
• Advise system owners, ISSOs, and program leadership on secure design alternatives and risk mitigation options
• Oversee continuous monitoring activities, including vulnerability scanning, patch management, and configuration compliance
• Lead development and maintenance of system security documentation and Body of Evidence (BoE) packages
• Coordinate with ISSMs, AOs, and other stakeholders to support and defend authorization decisions
• Evaluate proposed system changes for security impact and lead security input to change management processes
• Mentor junior security engineers and contribute to team-wide process improvement
• Stay current on emerging threats, vulnerabilities, and mitigation techniques relevant to the supported environment

The Senior ISSE is expected to have additional duties as assigned in support of corporate cybersecurity services. Additional details are reviewed in accordance with company policies.