Senior Information Systems Security Engineer

Leidos has an opportunity for a senior-level Information Systems Security Engineer to serve as the primary security engineering authority across complex, multi-enclave environments. This role supports the design, integration, and accreditation of secure networking and computing systems operating across multiple classification levels. The selected candidate will provide technical leadership in applying IA policy, RMF processes, and security engineering principles throughout the system lifecycle.

• Serve as the primary security engineering representative supporting the design, development, implementation, and integration of secure networking, computing, and enclave systems.
• Develop, decompose, and validate system security requirements to support secure architectures across multiple classification levels.
• Conduct technical security assessments to identify vulnerabilities, assess risk, and recommend mitigation strategies.
• Apply IA policies and RMF processes to support security planning, risk analysis, and authorization activities.
• Review Certification & Accreditation (C&A) documentation for completeness, accuracy, and compliance with established standards.
• Recommend system‑level security solutions and contribute to the development of enterprise security architectures.
• Support systems engineering activities including requirements development, baseline architecture design, simulation and analysis, and process improvement initiatives.

• 14+ years of Information Security experience with a Bachelor’s degree in Computer Science, Information Assurance, or related field OR 18+ years of directly related information security experience without a degree.
• Demonstrated experience supporting cross‑functional planning, coordination, and execution across full system integration activities.
• Strong working knowledge of RMF and Information Assurance policy implementation.
• Familiarity with cloud and edge computing, networks, data management, systems engineering, and C4
  
  ISR systems integration.
• Ability to collaborate effectively with multidisciplinary technical teams across varying levels of technical expertise.
• DoD 8570 compliant (IAM Level I or IAT Level II - e.g., CAP or Security+ CE).
• Active Top Secret/SCI clearance with Polygraph.

• Experience supporting AWS environments and cloud security integration.

At Leidos, we outthink, outbuild, and outpace the status quo - because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 - and moving faster than anyone else dares.

Original Posting: March 4, 2026

For U.S. Positions: While subject to change based on business needs, Leidos reasonably anticipates that this job requisition will remain open for at least 3 days with an anticipated close date of no earlier than 3 days after the original posting date as listed above.

Pay Range: $ - $

The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.

About Leidos

Leidos is an industry and technology leader serving government and commercial customers with smarter, more efficient digital and mission innovations. Headquartered in Reston, Virginia, with 47,000 global employees, Leidos reported annual revenues of approximately $16.7 billion for the fiscal year ended January 3, 2025. For more information, visit

Pay and Benefits

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