Information System Security Engineer

Leidos Corporate Information Security Office reporting through the Digital Sector is seeking an Information System Security Engineer to support various information systems and act as the Subject Matter Expect to Junior System Administrators. The successful candidate will be responsible for maintaining securing and supporting complex classified information systems as well as ensuring compliance with security protocols and regulations.

Location: This position is full time onsite at our Campus Point San Diego office.

Clearance: You must currently hold an active DoD Top Secret clearance to be considered and must be eligible to obtain Special Access Program and Special Compartmented Access (SCI) post hire.

Primary Responsibilities

This role includes a combination of duties to protect information and maintain security controls for an entire system site or program to reduce risk.

• Serve as the Information System Security Engineer (ISSE) for Special Access Program information systems providing security engineering support throughout the full system lifecycle from research and development through deployment accreditation operations maintenance and decommissioning.
• Design develop integrate and maintain secure classified information systems and architectures in accordance with the Joint Special Access Program Implementation Guide (JSIG) Risk Management Framework (RMF) applicable DoW policies and program-specific security requirements.
• Develop and maintain system security architecture including network segmentation boundary protections authentication privileged access encryption auditing logging secure communications virtualization storage and data protection solutions.
• Implement and validate DISA Security Technical Implementation Guides (STIGs) Security Requirements Guides (SRGs) vendor security guidance and program specific hardening requirements across Windows Linux network virtualization storage and supporting infrastructure.
• Coordinate with ISSMs ISSOs System Administrators and Program Management to resolve technical and compliance issues.
• Develop secure configuration baselines build procedures automation scripts and configuration management processes to improve repeatability and compliance across classified systems.
• Support troubleshooting and resolution of complex security and infrastructure issues involving a variety of information systems.
• Support the preparation for and execution of government security assessments authorization reviews inspections and audits including collection and presentation of objective evidence demonstrating control implementation.
• Provide technical cybersecurity guidance and mentoring to system administrators ISSOs and other program personnel.

Basic Qualifications

• Must be a U.S. Citizen.
• Bachelors Degree with 8-12 years of experience Masters degree with 6-10 years of experience or equivalent relevant experience and/or industry-standard certifications may be considered in lieu of degree.
• Must hold a current Active Top Secret security clearance to be considered along with sustained ability to be cleared to Special Access Programs and ability to obtain Top Secret/SCI security clearance.
• Must have a DoD 8140/8570 IAT level II or higher certification such as CompTIA Security.
• Professional-level knowledge and hands-on experience administering engineering or securing Windows and Linux operating systems including enterprise server and workstation environments.
• Expert-level knowledge of virtualization technologies enterprise storage platforms and backup/recovery solutions including the security considerations associated with each.
• Working knowledge of enterprise networking concepts and technologies including TCP/IP routing switching VLANs firewalls network segmentation DNS authentication and secure network architecture.
• 3 years of demonstrated experience supporting Special Access Program (SAP) environments and applying applicable cybersecurity requirements including the RMF and JSIG.
• Experience interpreting cybersecurity requirements and translating security controls into technical configurations engineering requirements and system implementations.
• Experience implementing assessing and maintaining technical security controls across operating systems networks virtualization platforms storage and supporting infrastructure.
• Hands-on experience implementing and maintaining DISA STIGs SRGs Nessus and secure configuration baselines.
• Knowledge of enterprise security technologies and concepts including Active Directory Group Policy endpoint security centralized logging auditing privileged access encryption and access control.
• Experience supporting the system development and security lifecycle including design integration testing deployment authorization continuous monitoring maintenance and decommissioning.
• Ability to troubleshoot complex technical and cybersecurity issues spanning operating systems networking or other information system components.
• Strong technical documentation and communication skills with the ability to clearly communicate security risks technical requirements remediation strategies and engineering recommendations to both technical and nontechnical stakeholders.
• Experience with the Risk Management Framework (RMF) and maintaining compliance artifacts such as SCAP scans STIGs and Nessus Vulnerability reports.
• Experience developing or maintaining technical procedures system build documentation configuration baselines work instructions scripts or automation used to support secure and repeatable system deployments.
• Experience designing or securing air-gapped environments including offline patching software repositories vulnerability management and configuration management.

Preferred Qualifications

• ISC(2) Certification Information System Security Professional (CISSP) or Information System Security Engineering Professional (CISSP-ISSEP) certification.
• RedHat Certified System Administrator (RHCSA) certification.
• Demonstrated ability to independently interpret JSIG/RMF controls and translate them into practical technical architectures configurations implementation guidance and validation procedures.
• Experience developing and maintaining SIEM/log-management platforms such as Splunk and endpoint security technologies to include DLP.

If youre looking for comfort keep scrolling. At Leidos we outthink outbuild and outpace the status quo because the mission demands it. Were not hiring followers. Were recruiting the ones who disrupt provoke and refuse to fail. Step 10 is ancient history. Were already at step 30 and moving faster than anyone else dares.

Original Posting:

October 8 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 $107900.00 - $195050.00

The Leidos pay range for this job level is a general guideline onlyand 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.

Required Experience:

IC