Senior Firewall Network Specialist

In this role you will maintain and advance the network security for a leading quantitative trading firm. You will collaborate with the Network Engineering team to design secure, auditable DMZs and automate standard practices across a multi-vendor environment. You’ll diagnose complex network issues, review audit logs, and work with Cyber Security to mitigate threats and vulnerabilities. This position combines hands-on network security with development-like automation to sustain high reliability with controlled hours. A clear impact is shaping secure, scalable infrastructure that underpins trading operations.

• Collaborate with Network Engineering on DMZ designs and deployments
• Troubleshoot network issues using packet captures and audit logs
• Support monitoring improvements via scripting and cross-team collaboration with Developers
• Work with Cyber Security to mitigate threats and address vulnerabilities
• Keep firewall policies aligned with security standards and business needs

• Experience deploying and maintaining mission-critical networks
• Hands-on firewall configuration and troubleshooting
• Strong knowledge of network security principles and technologies (TCP, ARP, BGP, OSPF, DHCP, DNS)
• Automating workflows with a practical intuition
• Experience in DMZ network design
• Good programming skills
• Clear and effective communicator
• Understanding of computer science fundamentals and passion for technology

• Clear and effective communicator
• Collaborative mindset
• Problem-solving mindset
• Firewall configuration and troubleshooting
• DMZ design
• Scripting/automation for monitoring and workflows