Network Security Engineer

Leidos is seeking an experienced Principal Network Security Engineer to design, engineer, and implement enterprise network security capabilities across a large, distributed network environment. The role is responsible for advancing network security architecture through the execution of strategic design and implementation efforts that improve the security posture, segmentation, access control, and resiliency of the enterprise network.

This position is responsible for overall network security engineering support across a broad range of efforts, including planning, designing, and evaluating the security components of the network. Duties include providing specifications for network security architecture, evaluating and recommending new technologies to enhance current capabilities, performing needs assessments, and directing the installation, configuration, testing, and tuning of network security infrastructure.

The successful candidate serves as a technical leader and subject matter expert — assessing the current security architecture, defining the controls and segmentation model the enterprise needs, building practical implementation plans with realistic risk and rollback provisions, and directing a team of engineers to deliver them under aggressive timelines.

Scope and Impact

Impact: Influences development of solutions that impact strategic project and program goals and business results. Recommends and develops new technical solutions, products, and security standards. Leads and manages the work of other technical staff that has significant impact on project results and outputs.

Complexity: Resolves highly complex problems through significant application of technical knowledge, conceptualization, reasoning, and interpretation. Develops solutions that are highly innovative and achieved through research and integration of best practices.

Communication: Communicates with government, program, cybersecurity, and technical leadership on matters of significant technical importance. Presents security architecture recommendations, implementation plans, risks, dependencies, and status to technical leadership, cybersecurity authorities, stakeholders, and approval boards, and works to build consensus around new concepts, practices, and approaches.

Knowledge: In-depth understanding of network security principles, theories, and concepts and their application across a range of programs. Serves as a subject matter expert within the network security domain.

Network Security Engineering and Architecture

Project Execution

Technical Leadership

Documentation

Develop and maintain engineering and operational documentation, including:

Key Success Factors

This position requires more than a firewall administrator working a change queue. It requires a security engineer who can look at an enterprise network, determine where the real exposure is, design the segmentation and control model that closes it, and sequence the implementation so the enterprise stays up while it happens.

The successful engineer is equally comfortable in the technical detail — policy, routing, identity, certificates, inspection, and automation — and in front of cybersecurity authorities and approval boards defending a design, its residual risk, and its dependencies.

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 $116,350.00 - $210,325.00

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.