We are seeking an experienced IT Security Engineer III to join the AEGIS Security Infrastructure Engineering team supporting the NASA AEGIS Program. This role is responsible for the design, engineering, implementation, and lifecycle management of enterprise network security infrastructure supporting NASA's mission-critical environments.
The IT Security Engineer III serves as a senior technical resource responsible for architecting, implementing, and supporting complex security solutions across a large-scale, multi-vendor enterprise environment. This position works closely with operations teams, architects, program leadership, and customer stakeholders to develop secure, scalable, and resilient infrastructure while ensuring compliance with NASA security standards and federal requirements.
Primary Responsibilities
Design, engineer, implement, and maintain enterprise network security solutions supporting NASA mission environments.
Lead engineering efforts involving Fortinet, Cisco ASA/Firepower, Secure Access Service Edge (SASE), Web Application Firewalls (WAF), VPN technologies, and other enterprise security platforms.
Serve as the technical lead for complex infrastructure deployments, modernization initiatives, and security enhancement projects.
Develop secure network architectures and provide technical guidance for new and existing enterprise environments.
Perform advanced troubleshooting, root cause analysis, and resolution of complex network security issues.
Develop implementation plans, engineering documentation, network diagrams, standards, and operational procedures.
Lead change management activities including technical reviews, implementation planning, and post-change validation.
Evaluate emerging security technologies and provide recommendations for adoption within the enterprise.
Collaborate with cybersecurity, network engineering, operations, cloud engineering, and customer stakeholders to deliver integrated security solutions.
Ensure enterprise security infrastructure complies with NASA, federal, and industry security requirements and best practices.
Mentor junior engineers and provide technical leadership across engineering initiatives.
Participate in after-hours maintenance windows and provide escalation support as required.
Basic Qualifications
Ability to obtain a Public Trust Clearance.
Bachelor's degree in Information Technology, Cybersecurity, Computer Science, or a related field, or equivalent experience.
7+ years of experience in network security, cybersecurity, or infrastructure engineering.
Strong understanding of enterprise networking including:
TCP/IP
Routing and Switching
BGP
OSPF
VLANs
NAT
High Availability
VPN technologies
Experience engineering and administering enterprise firewall platforms such as Fortinet and Cisco ASA/Firepower.
Experience designing and implementing secure network architectures within large enterprise environments.
Experience troubleshooting complex security and networking issues across multi-vendor environments.
Experience following structured change management and engineering lifecycle processes.
Strong written and verbal communication skills with the ability to present technical concepts to both technical and non-technical audiences.
Preferred Qualifications
Industry certifications such as:
Fortinet Network Security Expert (FCP, FCSS, FCX)
Cisco CCNP Security or CCIE Security
CISSP
GIAC certifications
Experience with:
Fortinet Security Fabric
Cisco ASA/Firepower
Secure Access Service Edge (SASE)
Web Application Firewalls (WAF)
IPsec VPN technologies
PKI and certificate management
Zero Trust architectures
Experience supporting cloud security platforms
Experience working in large enterprise, federal government, or Department of Defense environments.
Experience supporting highly available, mission-critical infrastructure.
Demonstrated ability to lead engineering projects and mentor junior engineers.
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.
July 28, 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 $107,900.00 - $195,050.00
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.
Leidos is a Fortune 500® innovation company rapidly addressing the world’s most vexing challenges in national security and health. The company's global workforce of 48,000 collaborates to create smarter technology solutions for customers in heavily regulated industries. Headquartered in Reston, Virginia, Leidos reported annual revenues of approximately $15.4 billion for the fiscal year ended December 29, 2023.
Leidos was cited for the meaningful work employees perform that is challenging, impactful, and aligned with our customers’ missions as reasons professionals want to work and stay at our company. Leidos has also been named to lists including Forbes’ Best Employers for Diversity, Forbes’ America’s Best Employers for Women, Military Times Best for Vets Employers, and Ethisphere Institute’s World's Most Ethical Companies®.
Employees enjoy career enrichment opportunities available through mobility and development and experience rewarding relationships with supportive supervisors and talented colleagues and customers. Employees appreciate our flexible work environment, allowing for and encouraging a true work-life balance. Our professionals are also excited about our Employee Resource Groups, like the Collaborative Outreach with Remote and Embedded Employees (CORE), which strives to create an environment where every employee, regardless of location, feels fully engaged as a valued employee of Leidos.
Your most important work is ahead, visit careers.leidos.com for our latest opportunities.
