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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Network Security Engineer - **Company:** The One Group - **Location:** Stevenage, UK - **Experience:** Expert - **Contract:** Permanent contract - **Skills:** Authentication Protocols, Cyber Security, Domain Name System (DNS), Internet Protocol Security (IP SEC), Intrusion Detection Systems, Virtual Private Networks (VPN), OSI Models, Network Security, Nagios, Network Architecture, Network Monitoring, Routing, Packet Analyzer, Paessler Router Traffic Grapher, Security Information and Event Management, TCP/IP, Virtual Local Area Networks, Flexi (Photoshop Plugin), Transport Layer Security, Load Balancing, Computer Network Technologies, Web Filtering, Information Technology, Drilldown, Purple Team (Cyber Security), Splunk, Cisco - **Published:** August 26, 2026 - **Apply:** https://www.collegerecruiter.com/job/2815095168-network-security-engineer ## About the Role * Strong understanding of core networking: TCP/IP, DNS, routing, switching, VLANs, load balancing * Hands-on experience with next-generation firewall technologies and advanced features (IPS/IDS, SSL decryption, DPI) * In-depth knowledge of IPSec, SSL/TLS, VPNs and authentication mechanisms * Experience with network monitoring tools (PRTG, Nagios or similar) * Ability to analyse complex traffic flows and identify threat patterns such as exploitation, C2, lateral movement, or exfiltration * Understanding of secure network architectures (DMZs, segmentation, internal zones) * Exposure to SIEM platforms (Splunk, LogRhythm, Darktrace) is beneficial * Experience interpreting OSI model behaviours and protocol-level diagnostics is advantageous * SC eligible with British citizenship ## Description Be among the first 25 applicants This range is provided by The ONE Group Ltd. Your actual pay will be based on your skills and experience - talk with your recruiter to learn more. Base pay range Direct message the job poster from The ONE Group Ltd Working Pattern: 24/7 shift rota on-site & on-call We're looking for a Network Security Engineer to join a high-performance security operations environment, protecting critical infrastructure and ensuring the resilience of complex enterprise networks. You'll work within a 24/7 Incident Response function, combining hands-on engineering with real-time threat detection, investigation, and remediation. Key Responsibilities: * Monitor, investigate and triage security events within a 24/7 SOC environment * Configure, maintain and troubleshoot enterprise firewalls (Cisco, Palo Alto, Checkpoint) * Manage secure proxy platforms such as Bluecoat or F5, including content filtering and SSL inspection * Lead deep-dive analysis using packet capture to identify malicious traffic and attacker behaviours * Implement secure changes across network architecture, ensuring compliance and best practices * Support continuous improvement through the optimisation of network security tools, including "purple team" feedback and hardening recommendations * Contribute to the standardisation of network security tooling and documentation * Collaborate with infrastructure, security and architecture teams to deliver robust, resilient network solutions About You: * Strong understanding of core networking: TCP/IP, DNS, routing, switching, VLANs, load balancing * Hands-on experience with next-generation firewall technologies and advanced features (IPS/IDS, SSL decryption, DPI) * In-depth knowledge of IPSec, SSL/TLS, VPNs and authentication mechanisms * Experience with network monitoring tools (PRTG, Nagios or similar) * Ability to analyse complex traffic flows and identify threat patterns such as exploitation, C2, lateral movement, or exfiltration * Understanding of secure network architectures (DMZs, segmentation, internal zones) * Exposure to SIEM platforms (Splunk, LogRhythm, Darktrace) is beneficial * Experience interpreting OSI model behaviours and protocol-level diagnostics is advantageous * SC eligible with British citizenship * Company bonus scheme * Pension contributions up to 14% * Paid overtime opportunities * Flexi-leave (up to 15 additional days) * Enhanced parental leave * Subsidised meals, free parking and excellent on-site facilities Seniority level * Mid-Senior level Employment type * Part-time Job function * Information Technology, Production, and Analyst Industries * Aviation and Aerospace Component Manufacturing * Defense and Space Manufacturing Referrals increase your chances of interviewing at The ONE Group Ltd by 2x Get notified about new Network Security Engineer jobs in Stevenage, England, United Kingdom. ## Related Videos - [How Cisco embraced a DevOps culture within its network engineering team](https://www.wearedevelopers.com/videos/99-how-cisco-embraced-a-devops-culture-within-its-network-engineering-team) - [Cyber Sleuth: Finding Hidden Connections in Cyber Data](https://www.wearedevelopers.com/videos/893-cyber-sleuth-finding-hidden-connections-in-cyber-data) - [An Applied Introduction to eBPF with Go](https://www.wearedevelopers.com/videos/1075-an-applied-introduction-to-ebpf-with-go) - [Security Pitfalls for Software Engineers](https://www.wearedevelopers.com/videos/726-security-pitfalls-for-software-engineers) - [Turning Container security up to 11 with Capabilities](https://www.wearedevelopers.com/videos/718-turning-container-security-up-to-11-with-capabilities) - [Computer Vision from the Edge to the Cloud done easy](https://www.wearedevelopers.com/videos/263-computer-vision-from-the-edge-to-the-cloud-done-easy) ## Related Articles - [9 Ways to Make Money Hacking](https://www.wearedevelopers.com/magazine/333-9-ways-to-make-money-hacking) - [Understanding and Mitigating Common Web Vulnerabilities](https://www.wearedevelopers.com/magazine/565-understanding-and-mitigating-common-web-vulnerabilities) - [Dev Digest 134 - Where pixels sing?](https://www.wearedevelopers.com/magazine/477-dev-digest-134-where-pixels-sing) - [The Most Popular IT Jobs on the Market](https://www.wearedevelopers.com/magazine/376-the-most-popular-it-jobs-on-the-market) - [IT Salaries in UK](https://www.wearedevelopers.com/magazine/288-it-salaries-in-uk) - [Data Engineer Salary UK](https://www.wearedevelopers.com/magazine/253-data-engineer-salary-uk)