Senior Infrastructure Engineer £450 Per Day, Inside IR35 6-Month Contract Didcot, Oxfordshire Your new company We're supporting a nationally significant scientific research organisation recognised for delivering some of the most advanced and high-impact projects in the UK. Their digital platforms underpin cutting-edge experiments, secure collaboration and large scale data processing, and they rely on a modern, resilient infrastructure estate to keep these environments running safely and efficiently. As part of their ongoing investment in core services, they are seeking an experienced Senior Infrastructure Engineer to maintain, support and enhance their Microsoft 365, server, storage and authentication systems. This is a place where your technical expertise will directly contribute to work used across the UK science and innovation landscape. Your new role You'll take responsibility for the hands-on support and maintenance of both on-premise and cloud-based infrastructure. Most of your time will be spent supporting Microsoft 365 and Active Directory services, ensuring user access, directory health, security controls and core collaboration tools remain stable and well maintained. Alongside this, you'll manage servers and virtual environments, resolve issues within the estate, and ensure systems are configured, patched and performing reliably. You'll be the person teams turn to when complex IT problems arise, using your experience to troubleshoot effectively, diagnose root causes and deliver practical solutions that keep systems running smoothly. You'll maintain documentation, support certificate and authentication services, contribute to monitoring and BAU operations, and help enforce security and backup standards across the environment. Close collaboration with other technical teams will be key in ensuring that infrastructure services meet the needs of users across the organisation. This is a hands-on engineering role, ideal for someone who takes pride in stability, reliability and technical problem-solving within a busy, mission-critical environment. What you'll need to succeed You will bring strong, practical experience gained over several years working in IT infrastructure, with a solid understanding of Microsoft 365, Exchange Online and Active Directory in both on-premise and multi-tenant environments. You'll be comfortable supporting servers, virtualised platforms and cloud technologies, and you'll have the confidence to resolve complex issues relating to identity, authentication, performance and system reliability. Experience working with monitoring tools, backups, disaster recovery, and security processes will be highly beneficial, as will familiarity with certificates, load balancing or Linux systems. You'll be someone who communicates clearly, works well with others and thrives in environments where priorities shift quickly. Strong troubleshooting skills, the ability to manage your workload and the discipline to produce clear documentation will all be important. ITIL awareness and relevant Microsoft or infrastructure certifications are advantageous. The ability to work on-site in Didcot two days per week is essential. What you'll get in return You'll join a collaborative organisation where infrastructure plays a vital role in enabling groundbreaking scientific work. You'll have the opportunity to work with a varied and modern technology stack, contribute to meaningful improvements, and operate in an environment that values technical precision and strong engineering practice. Your knowledge will be respected, your work will be appreciated, and your contribution will support a mission with genuine national impact. What you need to do now If you're an experienced Infrastructure Engineer looking for a senior contract where your skills will be put to meaningful use, get in touch today to discuss this opportunity further. Hays Specialist Recruitment Limited acts as an employment agency for permanent recruitment and employment business for the supply of temporary workers. By applying for this job you accept the T&C's, Privacy Policy and Disclaimers which can be found at hays.co.uk