Network Engineer III

In this role you will help architect, build, and sustain high-availability launch and test networks that span classified and unclassified enclaves. As a network-strong engineer with meaningful cyber depth, you will lead network design, implementation, and performance tuning while partnering with cyber teams to embed RMF-aligned protections and secure baselines into the infrastructure. You will design and plan network communications systems, produce specifications and detailed schematics, recommend hardware and software to meet present and future capacity requirements, test network designs, and evaluate emerging communications technologies.

You will join a customer-supported engineering team in the San Antonio, TX area and maintain deep technical expertise across routers, switches, firewalls, multiplexers, bridges, and gateways. This position is 100% onsite and requires an active Top Secret clearance with SCI eligibility.

Schedule
: full-time schedule.

• Design, plan, configure, and sustain complex, multi-node enterprise-scale networks spanning classified and unclassified enclaves, maintaining detailed schematics and specifications for routers, switches, firewalls, multiplexers, bridges, and gateways.
• Partner with customer ISSMs/ISSOs and cyber engineering teams to develop and implement network changes in environments operating under, or seeking, an ATO/IATT, keeping designs aligned to RMF requirements.
• Lead end-to-end testing and validation of network designs, verifying configurations and monitoring hardware and link performance for reliability, availability, and compliance with security policy.
• Develop and execute implementation plans for enhancements, upgrades, and migrations, coordinating with stakeholders to minimize service disruption and documenting all changes and rollback plans.
• Engineer and operate core network services (DNS, DHCP, NTP, AAA) and segmented architectures that enforce well-defined trust boundaries and enable controlled information sharing across enclaves.
• Implement and tune network-level security controls — firewalls, VPNs, ACLs, IDS/IPS, and NAC — in close coordination with cyber and security teams so protections are built in rather than bolted on.
• Support network operations including fault and performance monitoring, incident response, and change management, using NMS and log/SIEM platforms within an integrated NOC/SOC construct.
• Perform physical-layer installation work (fiber, patch panels, encryption devices), maintain accurate as-built documentation and configuration baselines, and brief technical options, trade-offs, risks, and recommendations to internal and external stakeholders.

• Bachelor's degree in a Science, Technology, Engineering, or Mathematics (STEM) discipline from an accredited institution and 8 years of related professional/military engineering experience; or a Master's degree in a STEM discipline and 6 years; or a Ph.D. in a STEM discipline and 4 years.
• U.S. citizenship with a current DoD Top Secret security clearance and SCI eligibility/access active within the last 24 months.
• DoD 8570 IAT Level II certification (e.g., Security+ CE) or equivalent prior to start.
• Hands-on experience planning, implementing, operating, and troubleshooting routed and switched IP networks (IPv4, OSPF, VLANs, VPNs, firewalls) in mission-critical or real-time environments, including administration of Microsoft and Linux networked systems and applying foundational cybersecurity practices (hardening, secure configuration, access control) alongside cyber/security teams.

• Proven experience as a network design authority or principal engineer for new deployments or major redesigns from concept through cutover, including high-…