Network Engineer

Falls Church, VA Cisco ACI at federal scale, and infrastructure that has to move without anyone downstream noticing. Sienna Systems is seeking a Network Engineer to join our U.S. Customs and Border Protection Enterprise Network Architecture & Engineering Services Support (ENAESS) team, in Ashburn, Virginia. This is the data center side of the CBP network: Cisco Application Centric Infrastructure fabric, F5 load balancing, Firepower firewalls, NetScout and IXIA instrumentation, and the circuits and DMZ architecture tying it together. The environment is large, well instrumented, and genuinely complex, with active migration and colocation work in front of it. Hybrid out of Ashburn with approximately 35% travel to data center and field locations. Why You'll Want This Role: $100,000 – $105,000 based on experience $5,000 signing bonus for candidates with an active CBP background investigation, payable after 60 days Cisco ACI at real scale, not a lab Migration and colocation work rather than a steady-state ticket queue A senior engineering bench alongside you to learn from Established DHS program with a long runway and a stable government customer 401(k) with 4% matching, immediate vesting, no restrictions 3 weeks Paid Time Off plus 11 Federal Holidays Hybrid out of Ashburn, Virginia Key Responsibilities: Engineer, design, test, and implement network solutions across on-premises and cloud environments. Work within and extend the Cisco Application Centric Infrastructure fabric. Implement and tune load balancing across F5 Local Traffic Manager and Global Traffic Manager. Support colocation implementation, data center migration, and equipment relocation activities. Develop and maintain design documentation — system design documents, topology diagrams, configurations — and route it through peer review and security approval before implementation. Coordinate change requests with stakeholders and follow change management procedures to minimize operational impact. Test networking hardware, software, configurations, and tools; remediate bugs and vulnerabilities; validate that new components integrate cleanly. Support software and firmware upgrades and patching, automating where possible. Provide escalation support for network and mission-critical application outages.