Sr. ISSE TS/SCI Poly

Sr. Information Systems Security Manager (ISSE)

Leidos has a new and exciting opportunity for a Sr. Information Systems Security Manager (ISSE) in our Intel Sector's Cyber & Analytics Business Area (CABA) . Our talented team is at the forefront in Security Engineering, Computer Network Operations (CNO), Mission Software, Analytical Methods and Modeling, Signals Intelligence (SIGINT), and Cryptographic Key Management. At Leidos , we offer competitive benefits , including Paid Time Off, 11 paid Holidays, 401K with a 6% company match and immediate vesting, Flexible Schedules, Discounted Stock Purchase Plans, Technical Upskilling, Education and Training Support, Parental Paid Leave, and much more. Join us and make a difference in National Security!


Job Summary


Leidos is seeking a Sr. Information Systems Security Manager (ISSE) to join a high-impact, multi-agency program serving the United States Space Force (USSF) / Space Systems Command (SSC), the United States Air Force (USAF), and other critical mission stakeholders. The selected individual will play key role in enhancing, testing, and deploying a large-scale Satellite Communications (SATCOM) system to an existing infrastructure. The ideal candidate brings deep expertise in public key infrastructure (PKI) and key management, excels at complex problem solving, and has a strong record of delivering results as part of a high-performing team in a fast-paced Agile Development environment. This position offers a unique opportunity to enhance the resilience and cybersecurity of mission-critical communications that protect our nation.

Primary Responsibilities:

• Validating and verifying system security requirements and establishing/reviewing system security designs for large-scale systems, major system elements, and interfacing systems that are part of a large complex network environment with geographically distributed components.
• Identifying and implementing appropriate information security architectures and functionality to ensure uniform application of security policy and enterprise solutions.
• Recommending and contributing to the development of technical solutions, products, and standards based on current and desired system security architecture.
• Assisting with the evaluation and mitigation of system security threats and risks throughout the program life cycle.
• Contributing to the security planning, assessment, risk analysis, risk management, certification and awareness activities for various system and networking operations.
• Effectively collaborating with other internal technical experts on a day-to-day basis.
• Communicating with program POCs regarding Security issues.
• Participating in program increment planning and related agile team activities.
• Working closely with System Engineering, Test Engineering, and Integration teams to ensure that the hardware and software architecture and implementation meet the security requirements for processing classified information.
• Analyzing and assessing system implementation against multiple security compliance policies and recommending and implementing enhancements.
• Assisting with the evaluation of new development on the operational security posture of the system.
• Evaluating, reviewing, and testing security-critical software and implementing and enforcing information systems security policies, standards, and methodologies.
• Auditing system security configuration settings using common methodologies and tools.
• Enforcing security strategies and policies that affect various components of the geographically distributed systems.
• Assisting with the evaluation of security solutions to ensure they meet customer specified requirements for processing classified information.
• Providing configuration management for security-relevant information system software.
• Evaluating security compliance requirements for new system features.
• Identifying and remediating security issues throughout the system.
• Supporting risk assessment, risk management, security control assessment, continuous monitoring, service design, and other IA program support functions.
• Working with development teams to enrich team-wide understanding of different types of vulnerabilities, attack vectors and remediation approaches.
• Planning and conducting security verification testing of relevant type 1 devices.

Basic Qualifications:

• Bachelor's degree in Computer Science, Information Assurance, Information Security System Engineering, or related discipline and at least 12 years of relevant experience. Master's degree and at least 10 years of relevant experience. Additional experience may be substituted for a Degree.
• Must have experience applying Risk Management Framework.
• Must have experience with IT security policy.
• Must have experience with common security tools, such as Nessus, NMAP and Wireshark hardware/software security implementation, communication protocol, encryption techniques/tools, and web services.
• Must have experience with or familiarity with secure configurations of commonly used desktop and server operating systems.
• Must be comfortable working on multiple systems and components simultaneously in various configurations.
• Must have strong verbal and written communications skills.
• Must be committed to adopting and adhering to best practices.
• Must be able to effectively plan and prioritize tasking and communicate clearly regarding technical options and trade-offs.
• Must be capable of performing high quality work both independently and with a team in a fast-moving environment.

• Clearance Required: Must have an active or current TS/SCI with Polygraph.

Preferred Qualifications:

• Experience with Defense in Depth Principals/technology (including access control, authorization, identification and authentication, public key infrastructure, network and enterprise security architecture) and applying risk assessment methodology to system development.
• Experience with security services management processes (i.e. assessing and auditing network penetration testing, anti-virus planning assistance, risk analysis, and incident response).
• Experience providing information assurance support for application development.
• Experience with penetration testing tools.
• Experience with scripting languages.
• DoD 8570 compliance with IASAE Level 2 or 3.
• Information Systems Security Engineering Professional (ISSEP) Certification and/or Computer Information Systems Security Professional (CISSP) Certification.
• Experience working with or in military Satellite Communications (SATCOM) organizations such as United States Air Force (USAF), United States Space Force (USSF), or another Agency.
• Experience working with Public Key Infrastructure (PKI)/ key management programs and technologies.

At Leidos , the opportunities are boundless. We challenge our staff with interesting assignments that allow them to thrive professionally and personally. For us, helping you grow your career is good business. We look forward to learning more about you - Apply today!

If you're looking for comfort, keep scrolling. 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:
June 1, 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:
Pay Range $131,300.00 - $237,350.00

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, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.