Senior ISSE TS/SCI Polygraph

About the role

Leidos has a new opportunity for a Sr. Information System Security Engineer in the Intel Sector's Cyber & Analytics Business Area (CABA). The team works in Security Engineering, Computer Network Operations (CNO), Mission Software, Analytical Methods and Modeling, Signals Intelligence (SIGINT), and Cryptographic Key Management. The position supports a high‑performing agile team using the Scaled Agile Framework (SAFe) and DEVOPS best practices across robust development, test, and production environments. You will help enhance system security architecture and cyber capabilities, manage multiple system security plans under the Risk Management Framework (RMF), manage cross‑domain capabilities, and support Security Verification Testing (SVT) of relevant Type 1 devices. An active TS/SCI Polygraph is required.

Responsibilities

• Validate and verify system security requirements; establish system security designs for large‑scale systems, major system elements, and interfacing systems in a geographically distributed network environment.
• Identify and implement appropriate information security architectures and functionality to ensure uniform application of security policy and enterprise solutions.
• Recommend and develop technical solutions, products, and standards based on current and desired system security architecture.
• Assess and mitigate system security threats and risks throughout the program life cycle.
• Lead and/or contribute to security planning, assessment, risk analysis, risk management, certification, and awareness activities for various system and networking operations.
• Collaborate effectively with internal technical experts on a day‑to‑day basis.
• Communicate with Program Managers and customer POCs regarding security issues of significant importance.
• Participate in Program Increment Planning and related agile team activities.
• Work closely with System Engineering, Test Engineering, and Integration teams to ensure hardware and software architecture and implementation meet security requirements.
• Analyze and assess system implementation against multiple security compliance policies; recommend and implement enhancements.
• Evaluate security solutions to ensure they meet customer‑specified requirements for processing information.
• Evaluate the impact of new development on the operational security posture of the system.
• Evaluate, review, and test critical software.
• Propose, assess, coordinate, implement, and enforce information systems security policies, standards, and methodologies.
• Audit and assess system security configuration settings using common methodologies and tools.
• Manage and enforce security strategies and policies affecting various components of geographically distributed systems.
• Provide configuration management for security‑relevant information system software.
• Serve as a subject matter expert in security architecture, advising Program Managers, customer technical experts, and internal program teams.
• Formulate security compliance requirements for new system features.
• Identify and remediate security issues throughout the system.
• Support risk assessment, risk management, security control assessment, continuous monitoring, service design, and other IA program support functions.
• Work with development teams to enrich team‑wide understanding of vulnerabilities, attack vectors, and remediation approaches.
• Plan and conduct security verification testing of relevant Type 1 devices.

Requirements

• Bachelor’s degree and 12 years of relevant experience.
• Solid understanding of security practices and policies with hands‑on vulnerability testing experience using customer tools.
• Experience applying the Risk Management Framework (RMF).
• Experience formulating and assessing IT security policy.
• Demonstrated knowledge of and experience with common security tools (e.g., Nessus, NMAP, Wireshark), hardware/software security implementation, communication protocols, encryption techniques/tools, and web services.
• Experience with secure configurations of commonly used desktop and server operating systems.
• Comfortable working on multiple systems and components simultaneously in various configurations.
• Strong verbal and written communication skills.
• Commitment to adopting and adhering to best practices.
• Ability to effectively plan and prioritize tasking and communicate clearly regarding technical options and trade‑offs.
• Capable of performing high‑quality work both independently and with a team in a fast‑moving environment.
• Active TS/SCI Polygraph clearance.

Preferred qualifications

• Five (5) years of experience with Defense in Depth principles/technology (access control, authorization, identification and authentication, public key infrastructure, network and enterprise security architecture) and applying risk assessment methodology to system development.
• DoD 8570 compliance with IASAE Level 2 or 3.
• Information Systems Security Engineering Professional (ISSEP) Certification.
• Certified Information Systems Security Professional (CISSP) Certification.
• Experience developing/implementing integrated security services management processes (assessing and auditing network penetration testing, anti‑virus planning assistance, risk analysis, incident response).
• Experience providing information assurance support for application development, including system security certifications and project evaluations for firewalls across development, design, and implementation.
• Experience with penetration testing tools.
• Experience with scripting languages.

Pay

Pay range: $131,300.00 – $237,350.00 per year. The range is a general guideline; actual compensation considers responsibilities, education, experience, knowledge, skills, abilities, internal equity, market data, and applicable bargaining agreements.

Benefits

• Paid Time Off
• 11 paid holidays
• 401(k) with 6% company match and immediate vesting
• Flexible schedules
• Discounted Stock Purchase Plans
• Technical upskilling, education and training support
• Parental paid leave

Original posting date: October 19, 2026. The requisition is expected to remain open for at least 3 days from that date.