Senior Infrastructure Administrator

Overview

Are you ready to shape the future of secure network and server infrastructure across a global organisation? At Expleo, we’re expanding our UK Infrastructure Team and looking for a skilled Senior Infrastructure Engineer who thrives in a hands‑on technical environment. If you’re passionate about designing resilient networks, solving complex challenges, and playing a critical role in large‑scale technology operations, this is the opportunity for you.

What’s in It for You?

• High‑impact work supporting secure, enterprise‑level servers & networks across UK and global teams
• A role where your expertise directly influences network & server performance, resilience, and security
• Opportunities to collaborate with talented engineers across Expleo’s global 3‑tier network structure
• Real ownership of architecture, troubleshooting and continuous improvement initiatives
• A culture built on collaboration, innovation and professional growth

• Design, deploy, and maintain functional LAN, WLAN, WAN & server infrastructure environments
• Configure and install network devices, servers, routers and supporting technologies
• Monitor network integrity, performance and security across multiple UK sites and assist colleagues across different geographies when required
• Troubleshoot complex issues escalated by the team and independently resolve them
• Implement and automate network tasks to improve efficiency
• Mentor and guide team members on technical topics
• Develop, test and oversee security solutions—including authentication and disaster recovery
• Maintain full documentation of all systems, configurations and processes
• Identify areas for optimisation relating to capacity, scalability and performance
• Maintain strong level of technical security for UK network & server infrastructures, participate in vulnerability assessments, remediations, security audits, prepare and provide evidence if required
• Maintain high levels of governance and compliance with both internal and external controls. i.e. Cyber Essentials Plus and ISO
  27001

• Bachelor’s degree in Computer Science, Engineering or a related field
• Professional certifications such as CCNA, CCNP (Security, Firewall specialisms highly valued)

• Strong background in network administration, switching and routing
• Excellent troubleshooting skills with the ability to work independently
• Strong grounding in Active Directory and policy management
• Knowledge of PAN-OS, SD WAN, Cisco IOS and Extreme Network operating systems
• Strong understanding of security frameworks and access control models
• Azure server and related services build, configuration and maintenance
• Managing backups Azure / Veeam
• Client device deployment / patching (Azure Arc / SCCM / WSUS / Intune)
• Technical knowledge, support, troubleshooting of MS on premises Active directory infrastructure & related services - international scale if possible – (domain controllers, DFS, GPO, replication, etc)
• Knowledge of MS Cloud services and relationships with on premises infrastructure (EntraID, AD connect)
• Knowledge of Microsoft 365 architecture, support, troubleshooting at least small scale (UK only), ideally international scale.

• Organisational skills with a track record of mentoring colleagues

• Experience using diagnostic, monitoring and network analysis tools
• Experience working with Windows and Linux Servers Hyper‑V, VMWare.
• Experience with firewall configuration and management (Palo Alto preferred)
• Hands‑on experience with TCP/IP and routing protocols including BGP and OSPF

• Collaborative working environment – we stand shoulder to shoulder with our clients and our peers through good times and challenges
• We empower all passionate technology loving professionals by allowing them to expand their skills and take part in inspiring projects
• Always working as one team, our people are not afraid to think big and challenge the status quo

• As a Disability Confident Committed Employer we have committed to:
• Ensure our recruitment process is inclusive and accessible
• Communicating and promoting vacancies
• Offering an interview to disabled people who meet the minimum criteria for the job
• Anticipating and providing reasonable adjustments as required
• Supporting any existing employee who acquires a disability or long term health condition, enabling them to stay in work at least one activity that will make a difference for disabled people

“We are an equal opportunities employer and welcome applications from all suitably qualified persons regardless of their race, sex, disability, religion/belief, sexual orientation or age”.

We treat everyone fairly and equitably across the organisation, including providing any additional support and adjustments needed for everyone to thrive