Principal Network Engineer

MANTECH seeks a motivated, mission-focused Principal Network Engineer to join our team in Chantilly, VA.

In this role, you will provide advanced engineering expertise to design, implement, secure, and sustain complex enterprise network environments supporting critical customer missions. You will collaborate across technical teams and customer stakeholders to deliver resilient, highly available, and secure network solutions while driving operational excellence and innovation.

Responsibilities include but are not limited to:

• Interact with engineers, cross-functional teams, and customers at multiple levels to gather, coordinate, and deliver technical information.
• Work closely with engineering teams to troubleshoot and build complex, highly available network topologies.
• Develop and manage comprehensive network monitoring and alerting strategies leveraging SNMP, flow analytics, packet inspection, and infrastructure telemetry to proactively identify performance degradation, capacity constraints, and service disruptions across complex enterprise and mission-critical environments.
• Lead complex network troubleshooting and root cause analysis across enterprise, data center, cloud, and hybrid environments, utilizing packet captures, routing analysis, traffic flow inspection, and protocol level diagnostics to rapidly identify and resolve service-impacting issues.
• Perform engineering support and system administration for applications and systems, including installation, configuration, maintenance, patching, and backup/restore activities.
• Provide Tier 2/3 maintenance and engineering support for deployed network and cybersecurity technologies.
• Support Assessment and Authorization (A&A) activities related to cybersecurity technologies, where applicable.
• Develop and implement automation solutions for repetitive project tasks and metrics collection using scripting, supporting testing and production deployment.
• Perform additional project and corporate duties as assigned to support customer mission requirements.

Minimum Qualifications:

• Bachelor?s degree or 4+ additional years of IT experience in lieu of degree.
• 7+ years of experience in cybersecurity or network engineering.
• Proficiency in configuring and optimizing routing protocols like BGP and OSPF.
• Direct experience implementing network virtualization and encapsulation technologies (EVPN-VXLAN, MPLS).
• Solid understanding of traffic management and security perimeter defenses, including load balancers, firewalls, and virtualized infrastructure.
• Experience troubleshooting web application traffic to include a strong understanding of HTTPS transactions and mutual TLS (mTLS).
• Strong understanding of Windows and Linux systems, operating system security practices, and network security concepts.
• Experience deploying, upgrading, and troubleshooting multi-vendor network equipment and solutions, such as Juniper, Palo Alto, F5, and Nutanix.
• Experience leveraging SNMP monitoring tools.
• Must have or be willing to obtain an IAT Level II (or higher) certification within 6 months of hire.

Preferred Qualifications:

• Knowledge of Cross Domain Solutions (CDS) technologies on the NCDSMO approved products list.
• Understanding of architectural principles such as defense in depth, resilience, and integrated security operations.
• Familiarity with federal cybersecurity guidance, including NIST SP 800-37 (Risk Management Framework) and NIST SP 800-137 (Information Security Continuous Monitoring).
• In-depth understanding and practical experience with LANs, firewalls, routers, and switches.
• Experience working in Agile environments.

Clearance Requirements:

• Must possess an active TS/SCI with Polygraph.

Physical Requirements:

• Must be able to remain in a stationary position 50% of the time.
• Must occasionally move about inside the office to access file cabinets, office machinery, or communicate with co-workers, management, and customers via email, phone, or virtual platforms, which may involve delivering presentations.