Senior Network Engineer (Squid Proxy & Palo Alto Security) in London

Senior Network Engineer

+3 months +

+Fully remote working

+SC cleared - current active clearance is essential for this role

+Inside IR35

+£95 - £105 ph

+Sole British nationals only - due to nature of the project

We are seeking an experienced Senior Network Engineer with deep expertise in Squid Proxy, Palo Alto Networks Next-Generation Firewalls (NGFW), and Application Identification (App-ID) technologies to support, maintain, and enhance enterprise network security services.
The successful candidate will be responsible for the design, implementation, administration, and optimisation of secure web access platforms, proxy services, and next-generation firewall infrastructures. The role will focus on delivering secure, resilient, and compliant network services while supporting business-critical customer environments.
This position requires strong troubleshooting skills, security-focused thinking, and extensive experience with web proxy technologies, application visibility, policy-based security controls, and enterprise networking.

Key Responsibilities

Squid Proxy Administration
* Design, implement, configure, and support Squid Proxy environments.
* Manage forward, reverse, and transparent proxy deployments.
* Configure and maintain ACLs, authentication services, and content filtering policies.
* Implement SSL inspection and certificate management solutions.
* Optimise proxy performance, caching, and web traffic handling.
* Support proxy migrations, upgrades, and platform refresh activities.
* Analyse proxy logs and user traffic patterns to improve service performance and security.

Palo Alto Firewall Administration
* Deploy, configure, and support Palo Alto Networks NGFW solutions.
* Design, implement, and maintain security policies aligned to business and customer requirements.
* Manage policy lifecycle including rule creation, optimisation, review, and cleanup.

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Security & Compliance
* Implement and maintain enterprise security controls.
* Support vulnerability remediation programmes.
* Participate in security audits and compliance assessments.
* Ensure proxy and firewall services comply with internal and customer security standards.
* Support Cyber Security teams during incident investigations and threat analysis.
* Monitor security alerts and recommend remediation actions.
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Required Technical Skills
Proxy Services
* Squid Proxy Administration
* ACL Configuration
* SSL Bump / Inspection
* Kerberos Authentication
* NTLM Authentication
* LDAP Integration
* Proxy High Availability
* Web Filtering

Palo Alto Technologies

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Essential Experience
* 5+ years supporting enterprise networking environments.
* Proven operational experience with Palo Alto Networks firewalls.
* Demonstrable experience implementing and managing App-ID security policies.
* Strong experience supporting Squid Proxy environments.
* Experience with security-focused network design and troubleshooting.
* Experience working in highly secure or regulated environments.
* Experience supporting production and customer-facing services.
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Certifications
Essential
* Palo Alto PCNSA or equivalent experience.
* CCNA / CCNP Enterprise.
* ITIL Foundation.

Desirable
* Palo Alto PCNSE.
* CISSP.
* CompTIA Security+.
* Azure Network Engineer Associate.
* Red Hat Certified System Administrator (RHCSA)

If you'd like to discuss this Senior Network Engineer role in more detail, please send your updated CV to (url removed) and I will get in touch.