Senior Network Security Engineer (Hybrid, London)

About the role

We are seeking a Senior Network Security Engineer to join our 24x7 NOC and provide dedicated support to a global banking customer in Central London. Reporting to the Head of NOC, you will work on‑site two days a week and collaborate closely with internal and customer teams.

Key responsibilities

• Create and modify device, firewall and routing configurations across Cisco, Fortinet and Palo Alto platforms.
• Monitor, manage and support highly secure, complex network environments, including daily health checks and incident response.
• Perform out‑of‑hours changes, on‑call escalation and support major incidents.
• Maintain design documentation, Visio diagrams and SolarWinds maps.
• Coordinate incident, change and problem management through ITIL processes and ITSM tools such as Jira and SharePoint.

Required profile

• Cisco CCNP Enterprise and CCNP Security certifications (essential).
• Fortinet NSE 4/5 certification (essential).
• Proven L2/L3 network support experience with Cisco FTD, ACI, Nexus, Catalyst, Palo Alto, Fortigate and F5 technologies.
• Experience with automation tools (Ansible, Catalyst Centre) and network monitoring (SolarWinds).
• Knowledge of cloud connectivity (Azure, AWS, GCP, OCI) and market‑data/trader platform support.

Required skills

• Cisco routing and switching (Nexus, Catalyst, IOS).
• Cisco security (FTD, ACI, ISE, Firepower).
• Fortigate firewall administration.
• Palo Alto Networks firewall configuration.
• F5 BigIP load balancing.
• SolarWinds network monitoring.
• Automation with Ansible and Catalyst Centre.
• ITIL Foundation and ITSM tooling (Jira, SharePoint).
• Cloud VPC design for Azure, AWS, GCP, OCI.
• Multicast and complex NAT troubleshooting.

What we offer

• 25 days annual leave.
• Pension scheme.
• Private health insurance.
• Enhanced maternity and paternity leave.
• Death‑in‑service life cover.
• Shopping discounts, cycle‑to‑work scheme, season ticket/gym loans.
• Online wellbeing centre.