Information System Security Engineer

Leidos; San Diego (CA); On-site; USD 108,000 - 195,000; Full time

Job summary

Leidos' Corporate Information Security Office is seeking an Information System Security Engineer (ISSE) to support classified information systems and advise junior system administrators. The role covers security engineering, RMF/JSIG compliance, and lifecycle support from development through decommissioning.

Applicants must hold an active DoD Top Secret clearance and be eligible for SAP/SCI access. Onsite work at Campus Point, San Diego, with strong emphasis on implementing STIGs, auditing, and

Qualifications

• Active DoD Top Secret clearance required.
• Bachelor's degree with 8–12 years of experience, or Master’s with 6–10 years, or equivalent.
• DoD 8140/8570 IAT level II+ certification (e.g., Security+).
• Extensive experience securing Windows and Linux systems and enterprise environments.
• Strong RMF and JSIG knowledge; experience with STIGs and Nessus.

Responsibilities

• Serve as the Information System Security Engineer (ISSE) for SAP information systems across full lifecycle.
• Design and maintain secure classified architectures per JSIG, RMF, and DoD policies.
• Develop security baselines, build procedures, and automation to ensure repeatable deployments.
• Coordinate with ISSMs, ISSOs, System Administrators, and management to resolve issues.
• Support government security assessments, authorization reviews, and audits.
• Provide cybersecurity guidance and mentoring to staff.

Skills

RMF

JSIG

IAT Level II

Top Secret clearance

Windows Administration

Linux Administration

Disaster Recovery

Education

Bachelor's Degree

Master's Degree

Tools

Nessus

Splunk

DLP

Job description

Description

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.
• Bachelor's Degree with 8-12 years of experience, Master’s 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 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:

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 $107,900.00 - $195,050.00

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.

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 www.Leidos.com.

Pay and Benefits

Pay and benefits are fundamental to any career decision. That's why we craft compensation packages that reflect the importance of the work we do for our customers. Employment benefits include competitive compensation, Health and Wellness programs, Income Protection, Paid Leave and Retirement. More details are available at www.leidos.com/careers/pay-benefits.

Securing Your Data

Beware of fake employment opportunities using Leidos' name. Leidos will never ask you to provide payment-related information during any part of the employment application process (i.e., ask you for money), nor will Leidos ever advance money as part of the hiring process (i.e., send you a check or money order before doing any work). Further, Leidos will only communicate with you through emails that are generated by the Leidos.com automated system - never from free commercial services (e.g., Gmail, Yahoo, Hotmail) or via WhatsApp, Telegram, etc. If you received an email purporting to be from Leidos that asks for payment-related information or any other personal information (e.g., about you or your previous employer), and you are concerned about its legitimacy, please make us aware immediately by emailing us at [e-mail].

If you believe you are the victim of a scam, contact your local law enforcement and report the incident to the U.S. Federal Trade Commission.

Commitment to Non-Discrimination

All qualified applicants will receive consideration for employment without regard to sex, race, ethnicity, age, national origin, citizenship, religion, physical or mental disability, medical condition, genetic information, pregnancy, family structure, marital status, ancestry, domestic partner status, sexual orientation, gender identity or expression, veteran or military status, or any other basis prohibited by law. Leidos will also consider for employment qualified applicants with criminal histories consistent with relevant laws.