Senior/Principle Security Infrastructure Engineer Permanent | £70,000 to £90,000 | Bristol (hybrid)Our client is seeking a Senior/Principle Security Infrastructure Engineer to provide technical leadership and hands-on expertise in securing enterprise infrastructure and networks. This role focuses on resilience, compliance, and integrity across a complex multi-technology environment.Key ResponsibilitiesDesign, build and maintain secure on-premises and cloud network and system architecturesHarden Microsoft Server/Desktop platforms, Active Directory, and Group PoliciesDeploy and manage MFA solutions (YubiKey, RSA) for enterprise identity and access protectionSecure virtualisation platforms (Hyper-V, VMware) and implement endpoint security (EDR, anti-malware, DLP)Operate and optimise SIEM tools (Splunk, Microsoft Sentinel) for threat detection and incident responsePerform vulnerability assessments using Qualys and Tenable, driving remediation and continuous improvementAlign security controls with ISO 27001, NIST, CIS, and Cyber Essentials, supporting audits and complianceSkills andamp; ExperienceProven experience in infrastructure or network security within enterprise environmentsStrong knowledge of Microsoft technologies (Windows Server/Desktop, Active Directory, Group Policy)Hands-on experience with MFA, virtualisation, and network security appliancesUnderstanding of SIEM operations, vulnerability management, and endpoint protectionFamiliarity with recognised security ..... full job details .....