We are seeking an experienced Secure Infrastructure andamp; Systems Engineer to join a specialist team delivering highly secure, mission-critical infrastructure within a UK Defence and National Security environment. This is a hands-on engineering role with a strong design focus, supporting the development of scalable, secure platforms and client-facing systems where security, resilience, and operational integrity are paramount. Key Skills andamp; Experience Windows 10/11 Engineering and OS Hardening Secure Gold Image Creation and Deployment Hypervisor Design, Deployment and Management (KVM or proprietary platforms) Infrastructure Design and Systems Engineering Identity andamp; Access Management and MFA Patch Management, Logging and System Administration Technical Documentation and Configuration Control Secure Infrastructure Delivery within Defence or National Security environments Essential Requirements Proven experience designing and building highly secure infrastructure. Strong knowledge of Windows internals and OS hardening aligned to NCSC and industry best practices. Experience deploying and supporting virtualised environments. Ability to work autonomously and deliver against strict project deadlines. Previous Defence or National Security sector experience. Clearance Active DV Clearance is essential. Due to programme requirements, only candidates holding current DV clearance can be considered. This is an excellent opportunity to join a