Senior Infrastructure Engineer (Windows & VDI)

Thorn SDS Ltd; Corsham; On-site; GBP 65,000 - 95,000; Full time

Benefits offered by this job

25 days annual leave

Employer pension contributions

Group Life Insurance

Dental & Health Cashback Plan

Wellbeing services

Training and certifications

Defence programme exposure

Operational impact

Job summary

Thorn SDS is seeking an experienced Senior Infrastructure Engineer (Windows & VDI) to join a major UK Defence programme. You’ll support Windows infrastructure and Virtual Desktop environments that underpin mission-critical systems, working with enterprise-scale Microsoft technologies to ensure resilience and security.

As part of the TLS team, you’ll deliver 2nd/3rd line support, incident management and ongoing infrastructure improvements within a highly secure UK environment.

Qualifications

• Experience administering Windows Server 2016, 2019 and 2022.
• Administration of Active Directory, Group Policy, DNS and DHCP.
• Managing Microsoft SQL Server environments.
• Experience with Citrix Virtual Apps & Desktops and/or VMware Horizon.
• Knowledge of ITIL service management processes.
• Experience in enterprise Windows infrastructure support.
• Strong network fundamentals and Windows application support.
• Performance tuning, patch management and infrastructure optimisation.
• Security-focused, defence environments are highly desirable.

Responsibilities

• Provide advanced 2nd and 3rd line support across enterprise Windows infrastructure and VDI environments.
• Investigate complex incidents and perform root cause analysis.
• Maintain critical Microsoft platforms and collaborate with networking and applications teams.
• Deploy operating system updates and security patches.
• Monitor infrastructure health, performance and capacity for maximum availability.
• Produce and maintain technical documentation and runbooks.
• Support ITIL-aligned incident, problem and change management processes.
• Work with service teams to improve platform resilience and performance.

Skills

Windows Server

Active Directory

Citrix

VMware Horizon

SQL Server

Group Policy

ITIL

Defence environment experience

Tools

Citrix Virtual Apps & Desktops

VMware Horizon

Job description

Windows Server | Active Directory | Citrix | VMware Horizon | SQL Server | Group Policy | Defence | ITIL

Help deliver the infrastructure behind the UK's critical defence operations.

Are you an experienced Infrastructure Engineer with expertise in Windows Server and Virtual Desktop Infrastructure?

We're looking for a Senior Infrastructure Engineer (Windows & VDI) to join a nationally significant UK Defence programme, supporting the Windows infrastructure and virtual desktop environments that enable critical operational capabilities across the UK and overseas.

If you enjoy solving complex infrastructure challenges, working with enterprise-scale Microsoft technologies and supporting systems where resilience and security are paramount, this is an opportunity to make a genuine impact while developing your career in one of the UK's most advanced secure IT environments.

About Thorn SDS

Thorn SDS is a specialist Managed Service Provider headquartered in Alton, Hampshire. We partner with organisations across the Space, Defence and Security sectors, connecting exceptional technical professionals with some of the UK's most challenging and rewarding programmes.

About the Programme

You'll be joining a major transformation programme modernising the Ministry of Defence's deployable IT capability.

The programme is replacing legacy communication and information systems with modern, resilient and secure platforms.

As part of the Through Life Support (TLS) team, you'll help ensure these critical services remain secure, available and fully operational throughout their lifecycle.

The Role

As a Senior Infrastructure Engineer (Windows & VDI), you'll provide advanced 2nd and 3rd line support across enterprise Windows infrastructure and Virtual Desktop environments that underpin mission-critical defence systems.

Working within the Service Operations and Resolver Group teams, you'll investigate complex incidents, maintain critical Microsoft platforms and collaborate with infrastructure, networking and application specialists to ensure services remain resilient, secure and highly available.

Please note: This role focuses exclusively on Microsoft Windows infrastructure and VDI technologies. Linux administration is not part of this position.

What You'll Be Doing

• Supporting, maintaining and troubleshooting enterprise Windows Server environments (2016, 2019 and 2022).
• Administering Active Directory, Group Policy, DNS, DHCP and core Microsoft infrastructure services.
• Managing Microsoft SQL Server environments.
• Providing advanced 2nd and 3rd line support across Windows infrastructure and VDI platforms.
• Supporting and maintaining Citrix Virtual Apps & Desktops and/or VMware Horizon environments.
• Deploying operating system updates, security patches and infrastructure improvements.
• Monitoring infrastructure health, performance and capacity to ensure maximum availability.
• Investigating complex technical issues and carrying out root cause analysis.
• Supporting ITIL-aligned incident, problem and change management processes.
• Working collaboratively with networking, application and service teams to improve platform resilience and performance.
• Producing and maintaining technical documentation, knowledge articles and operational procedures.

What We're Looking For

You'll be an experienced Infrastructure Engineer who enjoys working in secure, enterprise-scale environments and solving complex technical challenges.

You'll ideally have experience with:

• Windows Server 2016, 2019 and 2022 administration.
• Active Directory, Group Policy, DNS and DHCP.
• Microsoft SQL Server.
• Citrix Virtual Apps & Desktops and/or VMware Horizon.
• Enterprise Windows infrastructure support.
• ITIL service management processes.
• Network fundamentals and Windows application support.
• Performance tuning, patch management and infrastructure optimisation.
• Secure, regulated or defence environments (highly desirable).

You'll also have excellent analytical, troubleshooting and communication skills and be comfortable working full-time onsite in Corsham.

What's In It For You?

Alongside a competitive salary, you’ll receive:

• 25 days' annual leave plus Bank Holidays.
• Employer pension contributions.
• Group Life Insurance.
• Dental & Health Cashback Plan.
• Wellbeing services including GP access, physiotherapy and lifestyle savings.
• Thorn Wellbeing Support Contribution.
• Employee Referral Scheme.
• Supported training, certifications and professional development.
• The opportunity to work on one of the UK's most significant defence technology programmes.
• Exposure to enterprise-scale Microsoft infrastructure within a highly secure environment.
• The chance to collaborate with experienced engineers on technically complex projects that have a genuine operational impact.

Security Requirements

Applicants must have the right to work in the UK and either already hold, or be eligible to obtain, a high level of UK National Security Clearance.

Please note that, due to the nature of our work, nationality, previous nationalities and country of birth may affect eligibility for certain security-cleared positions.