Network Security Lead

Randstad NV; City Of London; Hybrid; GBP 70,000 - 80,000; Full time

Job summary

Randstad NV is seeking a senior, hands-on Network Security Lead in London. The role focuses on enterprise routing, multi-vendor firewalls, SDN, and hybrid cloud connectivity. You will serve as the L3 escalation authority and drive high-availability network operations in BPSS-governed environments.

Key responsibilities include incident management, vulnerability monitoring, and governance with CAB. The ideal candidate has 8+ years of experience and holds active BPSS clearance with hands-on

Qualifications

• 8+ years of enterprise network and security ops experience.
• Hands-on with next‑gen firewalls and VPN architectures.
• BPSS clearance or eligible for BPSS screening.

Responsibilities

• Serve as SME and escalation point for L3 network and security incidents.
• Oversee incident, change, and problem management per SLAs and CAB governance.
• Lead hardware/software lifecycle upgrades and configuration hardening across edge, campus, and core infrastructure.
• Provide 24/7 escalation coverage and on‑call participation.

Skills

Enterprise routing

Switching

Firewalls

NAC 802.1X

Python/PowerShell/Ansible

BPSS clearance

IPsec/SSL VPN

Incident management

Education

CCNP/CCIE (Enterprise or Security)

Tools

Palo Alto PAN-OS

Fortinet FortiGate

Cisco FTD

Cisco ISE

Job description

• Location: London, UK (Hybrid - 2 days on-site/week)


• Position Type: Full-Time, Permanent


• Salary: £70,000 - £80,000 per annum + Benefits

We are seeking a senior, hands‑on Network Security Lead with 8+ years of expertise spanning enterprise routing/switching, multi‑vendor firewalls, Software-Defined Networking (SDN), and hybrid cloud connectivity.

In this role, you will act as the principal L3 technical escalation authority and operational lead across our secure network estate. You will drive high‑availability network operations, lead major incident resolution, enforce rigorous security posture, and champion compliance within BPSS-governed and enterprise‑scale environments.

Key Responsibilities

Technical Leadership & Incident Management

• Serve as the senior Subject Matter Expert (SME) and primary escalation point for L3 network and security incidents, troubleshooting complex multi‑technology outages through to root cause analysis (RCA).


• Oversee enterprise incident, change, and problem management processes, ensuring strict alignment with SLAs, operational resilience, and Change Advisory Board (CAB) governance.


• Lead scheduled hardware/software lifecycle upgrades, firmware patching, and configuration hardening across all edge, campus, and core infrastructure.


• Provide escalation coverage within a 24/7 operational framework, participating in on‑call rotations and critical response scenarios.

Network Security, Firewalls & Access Control

• Administer, tune, and harden enterprise perimeter and internal firewalls across Palo Alto (PAN-OS), Fortinet (FortiGate), Cisco FTD, and Cisco Meraki.


• Design, deploy, and support enterprise Network Access Control (NAC) via Cisco ISE, covering 802.1X policy enforcement, posture assessment, guest access, and multi‑factor authentication (MFA) integrations.


• Monitor vulnerability advisories, evaluate threat profiles, execute remediation programs, and maintain adherence to audit baselines and BPSS (Baseline Personnel Security Standard) standards.

Core Routing, Switching & Infrastructure Operations

• Configure, optimize, and troubleshoot large‑scale data center and enterprise campus fabrics, including Cisco Nexus, Aruba, Dell, and HP hardware estates.


• Maintain advanced routing and data center protocols, including BGP, OSPF, EIGRP, VXLAN/EVPN, DMVPN, HSRP/GLBP, and VPC.


• Manage enterprise wireless infrastructures across Cisco, Aruba, and Meraki controllers and access points, ensuring optimized RF coverage and guest/corporate network isolation.

Governance, Continuous Improvement & Mentorship

• Identify and build operational automation scripts using Python, PowerShell, or Ansible to streamline routine configurations, backups, and health checks.


• Maintain clear operational documentation, Standard Operating Procedures (SOPs), network topologies, and knowledge‑transfer repositories.


• Mentor, train, and guide mid‑level network and security engineers, promoting best practices in technical governance and customer stakeholder communication.

Qualifications & Experience

Essential

• Experience: Minimum 8 years of dedicated experience delivering and supporting enterprise‑grade network and security operations.


• Routing & Switching: Proven mastery of Cisco data center and campus platforms (Catalyst, Nexus) and industry routing protocols (BGP, OSPF, VXLAN).


• Network Security: Deep hands‑on engineering background with next‑generation firewalls (Palo Alto, Fortinet, or Cisco FTD) and enterprise VPN architectures (IPsec, SSL).


• Identity & NAC: Practical deployment and troubleshooting experience with Cisco ISE or comparable 802.1X authentication systems.


• Security Clearance: Must hold active BPSS clearance or be fully eligible to undergo BPSS pre‑employment screening.

Desirable

• Prior experience in high-level or low-level Network Architecture & Design.


• Enterprise Cloud Networking experience across AWS, Azure, or GCP (e.g., Transit Gateways, DirectConnect/ExpressRoute, Virtual Appliances).


• Scripting capability for network automation (Python, REST APIs, Ansible).


• Professional certifications: CCNP / CCIE (Enterprise or Security), PCNSE, or equivalent vendor accreditation.