Senior Windows Platform Engineer - Secure On-Site London

Job Description: Salary Range: £60,000 - £71,400 Leonardo UK operates a grade-based salary framework with broad bands. The salary range shown reflects the approved grade band for this role, or a narrower hiring range published within that band, and is benchmarked against the external market. Exceptions above the standard range are managed through governance controls to protect internal equity. Your Impact Leonardo is looking for a 3rd Line Platform Engineer to join our collaborative and skilled team supporting a critical MOD site. This is an exciting opportunity to serve as a Subject Matter Expert (SME) in Windows-based enterprise infrastructures. You'll play a central role in the design, deployment, and support of high-security systems that underpin key defence and aerospace operations. This role is based full-time on site in London and requires DV clearance. What you will do as a Principal Platform Engineer: Take ownership of complex technical issues through to resolution, collaborating with users and other IT teams. Provide expert-level troubleshooting for incidents escalated from 1st and 2nd line support, ensuring consistent and minimal disruption to services. Deploy and integrate secure Windows Server environments (Active Directory, Group Policy, DNS, DHCP) using industry best practices. Implement and maintain infrastructure security measures such as patching, access controls, and hardening to align with compliance and internal governance. Use monitoring tools to proactively optimize system performance and ensure high availability. Create and maintain detailed technical documentation and contribute to internal knowledge sharing and mentoring. Participate in IT projects, ensuring infrastructure design meets both technical and business objectives. Collaborate closely with network, security, and application teams to deliver reliable, secure IT services. What you’ll bring: Proficiency in Ivanti Application