Network Security Specialist

In this role you help safeguard a mission-critical, multi-vendor trading network and drive standardisation through automation. You’ll work with a London-based, high-performing team that collaborates globally to keep networks secure, auditable, and aligned with business requirements. You’ll tackle complex security challenges across DMZ designs, firewall policies, and monitoring automation, making an impact on trading and internet connectivity. This is a hands-on, highly collaborative position with a focus on practical security delivery and efficiency.

• Collaborate with Network Engineering on DMZ designs and deployments
• Troubleshoot network issues via packet captures and audit log reviews
• Assist with monitoring improvements through scripting and cross-team collaboration with Developers
• Work with Cyber Security to mitigate threats and manage vulnerabilities
• Ensure firewall policies remain up to date with security standards and business requirements

• Extensive 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)
• Automation-oriented mindset with ability to automate workflows
• Experience in DMZ network design
• Good programming skills
• Clear and effective communicator
• Understanding of computer science principles and passion for technology

• Clear and effective communicator
• Collaborative mindset
• Problem-solving orientation
• Firewall configuration and troubleshooting
• DMZ design and deployments
• Network security protocols (TCP, ARP, BGP, OSPF, DHCP, DNS)