Network Engineer

Network Infrastructure Engineer / 6 month Freelance Contract / Hybrid London / Start ASAP

Key Responsibilities:

• You will work with the central network team to improve the reliability, security and repeatability of our network and infrastructure estate.
• Provide senior hands-on capacity for the network team while workload is high.
• Support incident response on live production networks, helping restore service, redundancy and failover.
• Operate, configure and troubleshoot a multi-vendor, multi-site network estate across London HQ and connected sites.
• Support wired and wireless networks, VPNs, DNS, DHCP, VLANs, segmentation, routing, switching and firewall policy.
• Execute network and infrastructure changes safely within established designs, standards and change-management practices.
• Build a staging network environment and CI pipeline for network changes, so MikroTik and Juniper configuration can be validated before reaching production.
• Support the team’s Juniper migration and infrastructure-as-code roadmap.
• Advance Terraform-based configuration management for MikroTik devices.
• Drive the Ubuntu 22.04 to 24.04 upgrade across relevant infrastructure and Linux systems.
• Automate network configuration and site setup using tools such as Terraform and Ansible.
• Contribute scripts, documentation and internal tooling that make infrastructure operations more repeatable and reliable.
• Apply strong network security practices across access controls, segmentation, certificate management, encryption and secure site-to-site connectivity.
• Collaborate with IT support, cloud infrastructure and engineering teams to maintain seamless hybrid connectivity between on-prem and cloud environments
• Act as senior engineering-level support for infrastructure and networking queries from on-site and remote teams.
• Document what you touch and transfer knowledge clearly so the permanent team can pick up work seamlessly at the end of the engagement.

Essential:

• 8+ years’ experience in infrastructure, networking, DevOps or a closely related field.
• Deep, hands-on Linux systems administration experience.
• Strong command of the Linux command line, package and service management, including systemd.
• Strong understanding of the Linux networking stack and production troubleshooting.
• Experience performing clean operating system upgrades across a fleet, ideally Ubuntu.
• Strong knowledge of networking protocols and core services, including TCP/IP, DHCP, DNS, routing, switching, VPNs, VLANs and firewalling.
• Hands-on experience across enterprise networking platforms such as Juniper, Cisco, MikroTik and Unifi.
• Proven experience delivering switch and firewall upgrades, cutovers and changes on live production networks.
• Experience providing senior support during major incidents.
• Strong network security experience, including segmentation, 802.1x, RADIUS, certificate infrastructure and secure site-to-site connectivity.
• Strong scripting skills in Bash and/or Python.
• Proven infrastructure-as-code experience using tools such as Terraform and Ansible.
• Experience using git and modern change-management practices.
• Experience operating in hybrid on-prem and cloud environments.
• Ability to work independently in a fast-moving, highly technical environment.
• Calm, decisive and pragmatic under pressure.
• A practical, delivery-focused mindset and the ability to ramp quickly.

Desirable:

• Experience in one or more of the following areas would be a strong advantage:
• Azure or other cloud infrastructure environments.
• Backfilling or covering a senior network role at short notice.
• Hands-on rollout of 802.1x, RADIUS and certificate infrastructure.
• Building network staging or test environments.
• Building CI pipelines for network configuration validation.
• Juniper migration programmes.
• Terraform-based management of MikroTik or other network devices.
• Multi-site enterprise networking environments.
• Hybrid on-prem and cloud connectivity.
• Fleet-based operations, data-offloading infrastructure or AI development environments.
• Automotive, robotics, autonomy, mapping, ML infrastructure or embodied AI environments.
• Senior networking certifications such as Juniper JNCIS/JNCIP, Cisco CCNP or equivalent.