Senior Infrastructure and Directory Services Engineer - Defence ProgrammeLocation: Caerphilly (with travel to Defence/Ministry of Defence sites as required)Clearance: SC (must hold or be eligible); DV highly desirablePackage: £65,000 + Bonus + comprehensive benefitsWorking Pattern: Hybrid (Mon and Fri optional WFH)This is a fantastic opportunity for you, a Senior infrastructure and Director Services Engineer - or similar, to join a long?established, financially robust technology provider with comprehensive experience delivering secure IT solutions across the UK public sector.The OpportunityA major Defence customer is undertaking an extensive programme to build a secure, on?premise, multi?domain virtualised infrastructure that underpins mission?critical and operational capabilities. As a Senior Infrastructure and Directory Services Engineer, you will design, implement, and support enterprise services across several secure domains - including Active Directory, identity services, Windows Server, DNS/DHCP, PKI, authentication platforms, and related Microsoft ecosystem components.Key Responsibilities- Architect, manage, and maintain multi?site Active Directory environments- Administer DNS, DHCP, and PKI in secure operational environments- Design and enforce Group Policy Objects (GPOs)- Manage Web Application Proxy (WAP), RDS, and federation services- Ensure alignment with MOD security standards- Participate in design reviews and Change Advisory Boards (CAB)- Work closely with secu