Duty engineer - senior infrastructure operations engineer (24/7 secure systems)

Duty Engineer - Senior Infrastructure Operations Engineer (24/7 Secure Systems)

Location: On-site, Northallerton, North Yorkshire
Department: Engineering
Section: Engineering
Reports To: Technical Director
Location: Secure UK Defence Environment
Contract Type: Permanent

Client: Our client is a specialist provider of secure ICT services supporting critical UK Defence systems. Operating within highly regulated, high-availability environments, they deliver resilient infrastructure, operational assurance, and rapid incident response across mission-critical platforms.

The engineering teams work at the forefront of secure networking, virtualisation, automation, and monitoring technologies to ensure Defence systems remain available, compliant, and secure 24/7.

Purpose of the Role: The Duty Engineer is a senior technical professional operating within secure Defence ICT environments, providing 24/7 operational support for mission-critical systems.

The role ensures system availability, resilience, security, and rapid incident resolution in line with contractual SLAs and KPIs, combining deep infrastructure expertise with modern automation and monitoring practices to deliver stable and compliant services.

You combine deep infrastructure expertise with modern automation and monitoring practices, enabling stable, efficient, and compliant service delivery within high-assurance environments.

The role operates as part of a structured 24/7 duty rota, requiring out-of-hours, on-call, and incident response support to maintain continuous operational service.

Key Responsibilities:

The successful candidate will be responsible for:

* Providing 24/7 operational duty support to ensure the availability, security, and performance of Defence ICT systems

* Acting as a technical first responder for incidents, alerts, and service degradation within secure environments

* Troubleshooting and maintaining LAN, WAN, MPLS, SD-WAN networks, firewalls, and VPN services

* Administering Active Directory and domain services, including DNS, PKI, RDS, WSUS, and related platforms

* Managing VMware virtualisation environments, including ESXi, vCenter, and VMware Cloud Foundation

* Operating and supporting ASTERIX VoIP systems

* Maintaining SIEM and monitoring platforms, including Splunk and Microsoft System Centre tooling

* Performing Linux system administration, patching, and security hardening

* Creating and maintaining automation using PowerShell, Ansible, and GitLab

* Supporting vulnerability remediation, compliance activities, and audit readiness

* Delivering incident response, root-cause analysis, and service restoration in line with agreed SLAs and KPIs

* Coordinating technical response and escalation to prevent incident impact or recurrence

Experience, Skills & Qualifications:

Essential / Highly Desirable:

* CCNA (or equivalent experience)

* LAN, MAN, and campus networking

* BGP, MPLS, VPLS, and VPN technologies

* Software-Defined Networking (VMware NSX) and SD-WAN

* Security systems administration, including IDS/IPS

* Active Directory, ADFS, PKI, DNS, DHCP, GPO, RDS, WSUS, WAP

* VMware vSphere, ESXi, and VMware Cloud Foundation administration

* ASTERIX VoIP systems

* SIEM & monitoring: Microsoft System Centre Suite, Splunk Enterprise / ES / ITSI

* Telemetry platforms: OpenTelemetry, Telegraf

* Linux administration and security patching

* Automation and scripting using PowerShell, Ansible, and GitLab

Application Process:

To apply, please submit your CV detailing your relevant experience and qualifications for the role. Applications will be reviewed on a rolling basis, so early submissions are encouraged.

Equal Opportunity Employer:

We value diversity and are committed to creating an inclusive work environment. We encourage applicants from all backgrounds to apply.

Contact: