Design, implement, and support enterprise network infrastructure including Cisco Nexus and spine-leaf fabrics, L2/L3 switching, routing protocols (BGP/OSPF/MPLS), VPNs, DNS, Palo Alto firewalls, F5/Citrix ADC load balancers, DMZ and Azure connectivity. Ensure network security controls, operate in large production environments with formal change management, and perform troubleshooting, analysis, and communication across teams.