Senior Network Engineer

We are looking for a Senior Network Engineer (L3) to take full technical ownership of our physical Data Centre (DC) operations, enterprise network routing, and perimeter network security. Following our infrastructure restructuring, this role focuses deeply on DC-to-DC connectivity, high-availability switching/routing, FortiGate firewall management, and supporting regular regulatory network drills (SBV & PCI DSS). Reporting to the Head of Infrastructure, you will ensure zero-downtime operations for core network pathways.

What You Will Do.

• AWS Cloud & Hybrid Network Operations: Operate, monitor, and troubleshoot AWS cloud network resources (VPCs, Subnets, Route Tables, Internet/NAT Gateways, Security Groups, NACLs, VPC Endpoints) and secure hybrid connections (AWS Direct Connect, Transit Gateway, VPC Peering, IPsec VPN).
• Data Centre & Physical Operations: Own end-to-end management of physical Data Centre (DC) network devices, racks, structured cabling, WAN/ISP links, and hardware maintenance schedules.
• Enterprise Routing & Switching: Maintain, optimize, and segment core routing and switching topologies (BGP, OSPF, VLANs, VXLAN, Spanning Tree) across Data Centers, office sites, and AWS cloud edges.
• Perimeter Security & Firewalls: Execute security policy definitions, NAT/VPN configurations, and zero-downtime firmware upgrades for FortiGate-Sophos enterprise firewalls and Network Access Control (NAC).
• Cloud Network Monitoring & Incident Response: Utilize CloudFlare, AWS CloudWatch, Network Firewall logs, Flow Logs, and enterprise NMS tools to proactively detect network bottlenecks, packet loss, or security anomalies.
• Disaster Recovery (DC-DR) & Regulatory Drills: Orchestrate cross-site network failover strategies and execute regular Disaster Recovery (DC-DR) network drills in compliance with State Bank of Vietnam (SBV) regulations
• VISA & SSL Certificate Management: Manage annual VISA ACS and SSL/TLS security certificate renewals to ensure seamless network transaction processing.
• L3 Escalation & Support: Serve as the Level-3 escalation point for complex cloud or on-premise connectivity incidents forwarded from internal IT Helpdesk specialists.

What We Are Looking For

• 3–5 years of hands-on experience in enterprise network engineering, AWS cloud networking, and perimeter security operations.
• Solid hands-on experience in operating AWS Cloud Networking: designing and managing VPCs, Multi-Account Routing, Transit Gateways, Direct Connect, Security Groups/NACLs, and VPC Peering.
• Deep expertise in FortiGate Firewalls (FortiOS),Sophos Firewall, IPsec VPNs, NAT, and Network Access Control (NAC).
• Strong mastery of core networking protocols: BGP, OSPF, MPLS, VLANs, Subnetting, VXLAN, and Spanning Tree.
• Direct experience managing physical Data Centre hardware, ISP links, and cross-connects.
• Practical experience using AWS CloudWatch, VPC Flow Logs, and network analysis tools (Wireshark) for deep troubleshooting.
• Experience executing zero-downtime maintenance and cross-site network DR failover drills.
• Familiarity with PCI DSS network compliance mandates and SBV regulatory standards.
• Professional English communication skills (written & spoken) for collaborating with regional engineering teams.

Nice to have

• Relevant certifications: AWS Certified Advanced Networking – Specialty, Fortinet NSE 4/7, or CCNP Enterprise/Security.
• Experience working in Digital Banking, Fintech, or high-availability payment processing environments.
• Basic Infrastructure as Code (Terraform) or scripting skills (Python/Bash) for cloud network automation.