Senior Engineer, Enterprise Infrastructure Services & Cloud in London

Colt provides network, voice and data centre services to thousands of businesses around the world, allowing them to focus on delivering their business goals instead of the underlying infrastructure.

We are seeking a highly skilled Senior Technical Subject Matter Expert (SME) to provide deep technical expertise across Enterprise Infrastructure Services. This role focuses on Windows Server, VDI, Citrix, Microsoft 365, and cloud platforms (Azure and GCP). The SME will act as a trusted advisor and hands-on technical authority, ensuring secure architecture, operational excellence, and driving automation and standardization initiatives to optimize cost and efficiency. The successful candidate will take ownership of technical solutions and assume responsibility for delivering outcomes that meet business objectives. While not directly responsible for virtualization, storage, and networking, the role requires a strong working knowledge of these areas to ensure seamless integration.

Responsibilities

• Serve as the go-to technical expert for Windows Server, Citrix, VDI, Microsoft 365, and cloud platforms (Azure & GCP).
• Provide advanced troubleshooting, root cause analysis, and resolution for complex incidents.
• Define and enforce best practices for infrastructure design, security, and governance.
• Drive automation and Infrastructure-as-Code initiatives for repeatable, secure deployments.
• Take ownership of technical deliverables and ensure successful implementation of solutions.

Infrastructure Operations Support

• Ensure operational stability and performance of Windows servers, Citrix environments, VDI platforms, and Microsoft 365 services.
• Maintain strong security posture and compliance across Azure and GCP environments.
• Collaborate with virtualization, storage, and networking teams to ensure integrated solutions.
• Assume responsibility for delivering outcomes aligned with business and security requirements.

Project & Architecture Contribution

• Contribute to infrastructure projects from design through implementation.
• Partner with cross-functional teams to deliver scalable, secure, and resilient solutions.
• Provide technical input for strategic roadmaps and architecture decisions.

On-call

• Participate in the Infrastructure Operations on-call rota to provide out-of-hours support for priority incidents.

What We’re Looking For

Required Technical Skills

• Windows & VDI: Advanced administration of Windows Server (2016/2019/2022). Expertise in Active Directory, Group Policy, DNS, DHCP, and PKI. Strong knowledge of Citrix Virtual Apps and Desktops architecture and VDI solutions.
• Microsoft 365: Deep understanding of M365 services, security, and compliance features. Experience with identity management (Azure AD), conditional access, and MFA.
• Cloud Platforms: Hands-on experience with Azure and GCP architecture, governance, and cost optimization. Familiarity with automation tools (PowerShell, Terraform) and DevOps principles.
• Virtualization, Storage & Networking (Working Knowledge): Understanding of VMware vSphere/ESXi architecture. Familiarity with enterprise storage technologies and SAN/NAS fundamentals. Solid grasp of networking principles and security best practices.
• Automation & Cost Optimization: Proven experience in automating infrastructure operations (patching, provisioning, monitoring). Ability to design and implement standardized processes to reduce complexity and cost.
• Linux (Desirable): Basic to intermediate experience with Linux systems (RHEL, Ubuntu, SUSE).

Leadership & Behavioural Skills

• Ownership & Accountability: Takes responsibility for delivering outcomes and driving technical excellence.
• Leadership: Ability to influence, guide, and collaborate across teams without direct authority.
• Outcome-Driven: Focused on delivering measurable results aligned with business objectives.
• Strategic Thinking: Aligns technical decisions with broader IT and business strategy.
• Communication: Clear and concise communication for technical and non-technical audiences, including senior leadership.
• Collaboration: Builds strong relationships across architecture, security, and operations teams.
• Adaptability: Thrives in a fast-paced, evolving environment.
• Continuous Improvement: Proactively identifies opportunities for optimization and innovation.

Qualifications

• Bachelor’s degree in Computer Science, Information Technology, or equivalent experience.
• Relevant certifications (Microsoft Certified: Azure Solutions Architect, Citrix Certified Expert, VMware VCP, Google Cloud Professional Architect) preferred.

What We Offer You

At Colt, you’ll make a difference. Because around here, we empower people. We don’t tell you what to do. Instead, we employ people we trust, who come together across the globe to create intelligent solutions. Our global teams are full of ambitious, driven people, all working together towards one shared purpose: to put the power of the digital universe in the hands of our customers wherever, whenever and however they want. We give our people the opportunity to inspire and lead teams, and work on projects that connect people, cities, businesses, and ideas. We want you to help us change the world, for the better.

Diversity and inclusion

Inclusion and valuing diversity of thought and experience are at the heart of our culture here at Colt. From day one, you’ll be encouraged to be yourself because we believe that’s what helps our people to thrive. We welcome people with diverse backgrounds and experiences, regardless of their gender identity or expression, sexual orientation, race, religion, disability, neurodiversity, age, marital status, pregnancy status, or place of birth.

Benefits

• Flexible working hours and the option to work from home.
• Extensive induction program with experienced mentors and buddies.
• Opportunities for further development and educational opportunities.
• Global Family Leave Policy.
• Employee Assistance Program.
• Internal inclusion & diversity employee networks.

When you join Colt you become part of our global network. We are proud of our colleagues and the stories and experience they bring.