Networking & Security Engineer

We are seeking a hands-on Network & Security Engineer with deep expertise in Cisco networking, firewall management, and SD-WAN, combined with a strong security-first mindset. Networking and security are the core priorities of this role. The successful candidate will take a leading part in designing, maintaining, and strengthening the firm's network and security infrastructure in response to an increasingly sophisticated threat landscape, including emerging risks associated with AI. This is a technically demanding role that combines hands-on network engineering with proactive security ownership. The successful candidate will act as a security-first thinker across everything they touch (from day-to-day network operations through to strategic infrastructure design) and will be expected to drive meaningful improvements to the firm's network architecture and defensive capabilities. This role is office-based and requires five days per week on-site presence. Key Responsibilities Design, implement, and maintain the firm's network infrastructure, including Cisco routers, switches, firewalls, VPNs, and wireless systems, ensuring high availability, performance, and security at every layer. Own and manage the firm's SD-WAN architecture, including deployment, configuration, optimisation, and ongoing management of SD-WAN fabric across all sites. Manage and continuously improve firewall infrastructure, including rule-base management, policy design, segmentation, and regular firewall audits to ensure a tightly controlled network perimeter. Lead the firm's security operations function, owning threat detection, incident response, and vulnerability management end-to-end, with network traffic analysis as a core input. Monitor, triage, and respond to security events across the network and wider environment, including log analysis, anomaly detection, and threat hunting, with strong awareness of modern and AI-enabled attack vectors. Own and drive security hardening across network devices, servers, endpoints, and cloud-adjacent systems, ensuring consistent application of best practices and compliance with security policies. Design secure network architecture, embedding segmentation, access control, and security requirements from the outset rather than retrofitting them. Conduct regular network and vulnerability assessments and penetration testing exercises, prioritising and remediating findings in a timely manner. Manage and continuously improve security tooling, including SIEM, EDR, IDS/IPS, and endpoint protection platforms, with particular focus on integration with network infrastructure. Act as the escalation point for network and security-related incidents across 2nd and 3rd line, providing expert guidance and driving resolution. Operate across Windows and Linux (Red Hat/CentOS) environments, ensuring both are maintained to a consistent security baseline and integrate cleanly with network infrastructure. Collaborate with infrastructure and technology teams to embed secure network design into project delivery and BAU processes. Develop and maintain network and security documentation, including network diagrams, firewall rule documentation, incident response playbooks, SOPs, and runbooks. Stay current with evolving networking technologies and the threat landscape, bringing proactive recommendations to improve the firm's network architecture and security posture over time. Participate in an on-call rotation to support critical network and security systems and respond to incidents outside business hours. Requirements Minimum 7+ years’ experience in infrastructure, networking, and security roles Strong hands-on experience with Windows Server and Linux (Red Hat/CentOS) Solid networking knowledge, including TCP/IP, VLANs, VPNs, DNS, DHCP, with practical experience in Cisco environments Demonstrated experience implementing and supporting security controls, including: Patch management and system hardening Endpoint protection and monitoring Identity and access management Good understanding of cyber security principles, including modern threat landscapes and evolving risks (e.g. automation and AI-driven attack vectors) Experience with virtualisation (VMware) and enterprise storage (SAN/NAS) Scripting or automation experience (e.g. PowerShell, Bash) is advantageous Experience in financial services or regulated environments is preferred Strong troubleshooting skills with a structured and analytical approach Able to balance BAU responsibilities with project delivery effectively A thoughtful and forward-looking mindset, with the ability to identify risks and propose improvements Clear and confident communicator, able to engage with both technical and non-technical stakeholders Self-motivated, accountable, and willing to take ownership of issues end-to-end Collaborative and adaptable, with a practical and solutions-focused approach