Senior Network Engineer; Squid Proxy & Palo Alto Security

Kent / Hybrid - 2 days per week onsite

Up to 780 per day inside ir35

Active SC clearance
- Sole UK National

We are seeking an experienced Network Architect / Senior Network Engineer with strong hands‑on expertise in Squid Proxy, Palo Alto Next-Generation Firewalls (NGFW) and App- to support and enhance secure enterprise network infrastructure.

This is an excellent opportunity for a technically strong network security specialist to take ownership of critical proxy and firewall services, focusing on secure web access, application visibility, security policy management and network optimisation.

• Design, implement, configure and support enterprise Squid Proxy environments, including forward, reverse and transparent proxy deployments.
• Administer and optimise Palo Alto Next-Generation Firewalls, including Panorama management.
• Develop and maintain granular firewall security policies using Palo Alto App-, User
  - Content-.
• Configure and manage URL filtering, Threat Prevention, Wild Fire, Global Protect and SSL decryption.
• Manage proxy ACLs, authentication integrations, SSL inspection and web filtering policies.
• Review and optimise firewall rule bases, transitioning legacy port-based rules towards application‑aware security policies.
• Troubleshoot complex network and application connectivity issues across Layers 2-7.
• Perform packet analysis using tools such as Wireshark and tcpdump.
• Support firewall and proxy upgrades, migrations, patching and high‑availability configurations.
• Work alongside Cyber Security teams to support vulnerability remediation, incident investigations and security compliance activities.

• 5+ years' experience supporting enterprise network infrastructure.
• Strong hands‑on administration and support experience with Palo Alto Networks firewalls
  .
• Demonstrable experience configuring and managing Palo Alto App- policies
  .
• Extensive experience with Squid Proxy
  , including ACLs, SSL inspection and authentication.
• Experience with Palo Alto Panorama, User-, URL Filtering and Threat Prevention.
• Strong understanding of TCP/IP, routing, VLANs, DNS, DHCP, NAT and VPN technologies.
• Experience troubleshooting SSL/TLS, authentication and application connectivity issues.
• Proficiency with network analysis tools such as Wireshark and tcpdump.
• Experience working within highly secure, regulated or business‑critical environments.

• Experience with in Defence, Government or Critical National Infrastructure (CNI).
• Experience supporting secure customer environments.
• Knowledge of network segmentation and Zero Trust security principles.
• Experience with infrastructure automation using Python or Ansible.
• Familiarity with monitoring platforms such as Splunk, Solar Winds, ELK or Grafana.