L3 Network Security Engineer

NTT SINGAPORE PTE. LTD.; Singapore; On-site; SGD 120,000 - 180,000; Full time

Job summary

NTT Singapore Pte. Ltd. is seeking an experienced L3 Network Security Engineer to design, implement and maintain enterprise network and security infrastructure across data centers, campuses, and cloud environments.

You will automate operations using Python, Ansible, and REST APIs while collaborating with cybersecurity, cloud, and application teams. The role emphasizes advanced routing, switching, firewall policies, and threat mitigation in highly available, mission-critical environments with a

Qualifications

• Bachelor's Degree in Computer Science, Information Technology, Engineering, or related discipline.
• Minimum 5 years of experience in enterprise network and security engineering.
• CCIE Certification.
• Strong hands-on experience supporting and administering Cisco Networking Technologies, Palo Alto Firewalls, Check Point Firewalls, Fortinet Firewalls, F5 Load Balancers, Infoblox DDI Solutions.
• Expertise in routing and switching protocols including BGP, OSPF, EIGRP, RIP, MPLS, VLANs, VPN Technologies.
• Proven experience in infrastructure automation using Python, Ansible, REST APIs, and Infrastructure as Code (IaC).
• Strong understanding of network security principles, segmentation, firewall policies, and threat mitigation.
• Experience supporting highly available and mission-critical environments.
• Excellent troubleshooting, analytical, and problem-solving skills.

Responsibilities

• Provide Level 3 technical support for complex network and security incidents, ensuring high availability and performance of enterprise infrastructure.
• Design, implement, and maintain large-scale network security solutions across data center, campus, and cloud environments.
• Manage and support security platforms including Cisco, Palo Alto Firewalls, Check Point Firewalls, Fortinet Firewalls, F5 Load Balancers, Infoblox DDI.
• Lead troubleshooting and root cause analysis for critical network and security issues.
• Develop and implement automation solutions to improve operational efficiency and reduce manual processes.
• Create automation scripts and workflows using Python, Ansible, and API integrations.
• Collaborate with cybersecurity, cloud, infrastructure, and application teams on security architecture reviews and project implementations.
• Participate in infrastructure transformation initiatives, network modernization, and security enhancement projects.
• Maintain technical documentation, operational procedures, and network standards.

Skills

Network security engineering

Infrastructure automation

Python scripting

Ansible automation

REST APIs

Infrastructure as Code

Education

Bachelor's Degree in Computer Science / IT / Engineering

CCIE Certification

Tools

Cisco Networking

Palo Alto Firewalls

Check Point Firewalls

Fortinet Firewalls

F5 Load Balancers

Infoblox DDI

Job description

About the Role

We are seeking an experienced L3 Network Security Engineer to our Infrastructure and Cybersecurity team. The successful candidate will be responsible for the design, implementation, optimization, automation, and operational support of enterprise network and security infrastructure across mission-critical environments. This role requires deep technical expertise in network security technologies and a strong focus on infrastructure automation.

Key Responsibilities

• Provide Level 3 technical support for complex network and security incidents, ensuring high availability and performance of enterprise infrastructure.


• Design, implement, and maintain large-scale network security solutions across data center, campus, and cloud environments.


• Manage and support security platforms including: Cisco (Routing, Switching, ACI, SD-WAN) Palo Alto Networks Firewalls Check Point Firewalls Fortinet Security SolutionsF5 Load Balancers (LTM/GTM) Infoblox DDI (DNS, DHCP, IPAM)


• Lead troubleshooting and root cause analysis for critical network and security issues.


• Develop and implement automation solutions to improve operational efficiency and reduce manual processes.


• Create automation scripts and workflows using Python, Ansible, and API integrations.


• Collaborate with cybersecurity, cloud, infrastructure, and application teams on security architecture reviews and project implementations.


• Participate in infrastructure transformation initiatives, network modernization, and security enhancement projects.


• Maintain technical documentation, operational procedures, and network standards.

Required Qualifications

• Bachelor's Degree in Computer Science, Information Technology, Engineering, or related discipline.


• Minimum 5 years of experience in enterprise network and security engineering.


• CCIE Certification


• Strong hands-on experience supporting and administering:Cisco Networking TechnologiesPalo Alto FirewallsCheck Point FirewallsFortinet FirewallsF5 Load BalancersInfoblox DDI Solutions


• Expertise in routing and switching protocols including:BGPOSPFEIGRPMPLSVLANsVPN Technologies


• Proven experience in infrastructure automation using:PythonAnsibleREST APIsInfrastructure as Code (IaC)


• Strong understanding of network security principles, segmentation, firewall policies, and threat mitigation.


• Experience supporting highly available and mission-critical environments.


• Excellent troubleshooting, analytical, and problem-solving skills.

Preferred Qualifications

• PCNSE, CCNP Security, Check Point CCSA/CCSE, NSE4/NSE7, or F5 certifications


• Experience with cloud networking and security (AWS, Azure, GCP)


• Knowledge of SASE, Zero Trust Architecture, SD-WAN, and Network Access Control (NAC)


• Experience in financial services, banking, or regulated enterprise environments


• Exposure to DevOps and CI/CD practices