Sr Principal Systems Security Engineer

About the role

The Senior Principal Systems Security Engineer will lead the integration of security engineering practices across the full systems development lifecycle (SDLC) for mission-critical DoW programs. This role is grounded in the principles of NIST SP 800-160 (Systems Security Engineering) and emphasizes proactive security-by-design rather than reactive compliance.

Responsibilities

• Lead systems security engineering activities across all phases of the SDLC, including concept definition, requirements analysis, architecture and design, implementation, integration, verification and validation, deployment, and sustainment
• Define, decompose, and allocate security requirements to system elements (hardware, software, firmware, and interfaces) ensuring traceability from threat models through verification evidence
• Develop and maintain security architectures, including protection strategies, trust boundaries, security-relevant data flows, and attack surface analyses for complex DoD systems
• Conduct and lead threat modeling, Systems-Theoretic Process Analysis for Security (STPA-Sec), and adversarial analysis to inform design trades and risk acceptance decisions
• Drive the integration of security into Development Security Operations (DevSecOps) pipelines, including automated security testing, static/dynamic analysis, container security, and secure CI/CD practices
• Lead Assessment and Authorization (A&A) activities for DoD systems in accordance with the Risk Management Framework (RMF), including security control selection, implementation, assessment, and continuous monitoring
• Author and maintain security engineering artifacts including System Security Plans (SSPs), Security Concepts of Operations (CONOPS), Security Control Traceability Matrices (SCTMs), and risk assessment reports
• Evaluate and apply applicable STIGs, SRGs, and security benchmarks to system components, and develop Plan of Action and Milestones (POA&Ms) for residual risks
• Provide technical leadership and mentorship to cybersecurity engineers, systems engineers, and software developers on secure design principles and security engineering best practices
• Engage with government customers, authorizing officials, and cross-functional program teams to communicate security posture, risk decisions, and compliance status
• Support proposal development, technical volume writing, and independent review of security architectures for new business pursuits

Requirements

Required Education, Experience, & Skills:

• Lead systems security engineering activities across all phases of the SDLC, including concept definition, requirements analysis, architecture and design, implementation, integration, verification and validation, deployment, and sustainment
• Define, decompose, and allocate security requirements to system elements (hardware, software, firmware, and interfaces) ensuring traceability from threat models through verification evidence
• Develop and maintain security architectures, including protection strategies, trust boundaries, security-relevant data flows, and attack surface analyses for complex DoD systems
• Conduct and lead threat modeling, Systems-Theoretic Process Analysis for Security (STPA-Sec), and adversarial analysis to inform design trades and risk acceptance decisions
• Drive the integration of security into Development Security Operations (DevSecOps) pipelines, including automated security testing, static/dynamic analysis, container security, and secure CI/CD practices
• Lead Assessment and Authorization (A&A) activities for DoD systems in accordance with the Risk Management Framework (RMF), including security control selection, implementation, assessment, and continuous monitoring
• Author and maintain security engineering artifacts including System Security Plans (SSPs), Security Concepts of Operations (CONOPS), Security Control Traceability Matrices (SCTMs), and risk assessment reports
• Evaluate and apply applicable STIGs, SRGs, and security benchmarks to system components, and develop Plan of Action and Milestones (POA&Ms) for residual risks
• Provide technical leadership and mentorship to cybersecurity engineers, systems engineers, and software developers on secure design principles and security engineering best practices
• Engage with government customers, authorizing officials, and cross-functional program teams to communicate security posture, risk decisions, and compliance status
• Support proposal development, technical volume writing, and independent review of security architectures for new business pursuits

Preferred Education, Experience, & Skills

• Master’s degree in Systems Engineering, Cybersecurity, or related field
• Active TS/SCI security clearance
• CISSP, ISSEP (Information Systems Security Engineering Professional), or equivalent certification
• Experience with Model-Based Systems Engineering (MBSE) tools (e.g., Cameo, SysML) applied to security architecture
• Familiarity with System-Theoretic Process Analysis for Security (STPA-Sec) tooling and processes
• Experience with zero trust architecture design principles and implementation
• Knowledge of cross-domain solutions, multi-level security architectures, and secure system integration patterns
• Experience supporting security engineering for embedded systems, real-time systems, or weapon system platforms

Pay

Full-Time Salary Range: $132962 - $226035