Our client, a prominent organisation within the Defence & Security sector, is currently seeking a Senior IT Infrastructure & Support Engineer for a permanent position. This role is pivotal in ensuring the reliability, security, and efficiency of the organisation's IT systems, contributing significantly to the resilience of business-critical systems, including ERP and cybersecurity tools. The role also involves maintaining and developing core infrastructure while fostering the professional growth of the IT team. Key Responsibilities: Provide high-level technical support across the business, including troubleshooting complex issues with infrastructure, applications, and user devices. Maintain and support key systems such as Active Directory, Azure, Exchange 365, virtualised environments (Hyper-V), and backup solutions. Contribute to the security and stability of the organisation's IT estate by supporting cybersecurity tools and policies. Collaborate with the wider IT team on system improvements, deployments, and technical projects. Proactively identify areas for automation, standardisation, or process improvement within IT operations. Act as a technical mentor to junior team members, providing guidance, informal training, and support with their development goals. Document solutions, processes, and best practices to build team knowledge and reduce single points of failure. Participate in disaster recovery planning, testing, and ser...