Deep, hands-on production experience with FortiGate and FortiOS — policy design, routing, HA, VDOMs, IPsec/SSL VPN, IPS/UTM profiles, and troubleshooting with CLI diagnostics (diagnose debug flow, sniffer, session table analysis). Significant WAN experience: BGP and OSPF at scale, IPsec and DMVPN-style overlays, MPLS/VPLS, broadband and LTE/5G failover, carrier circuit provisioning and troubleshooting, and WAN performance optimization.