Security Application Design Engineer Onsite in BracknellEligible for DV clearance£50-55K per annum + benefits packageJoin a high-impact engineering team delivering a secure Gateway solution for a major UK defence customer. This is a hands-on Security Application Architect role where you''ll design, implement and troubleshoot mission-critical infrastructure in a live, security-sensitive environment. Working alongside senior architects and engineering leads, you''ll play a key role in maintaining availability, supporting operational teams, and driving technical change across complex systems.What You''ll Be DoingIdentify and implement infrastructure and application changes to support Gateway functionality and availabilityProduce detailed technical designs for change alongside the customer and Programme ManagerWork daily with the Solution Owner and Engineering Lead to deliver engineering outcomesProvide technical support to SOC and 3rd Line teams, troubleshooting complex incidentsConfigure and support Gateway appliances and associated softwareMaintain high availability, resilience and security postureYour Technical BackgroundYou''ll bring strong hands-on experience across:InfrastructureVMware/vSphereRHEL andamp; Windows ServerTrellixSIEM platformsLinux andamp; ScriptingShell ScriptingREGEXFirewall configurationMicrosoft StackActive DirectoryDNSRDSApplications andamp; ProtocolsLDAPEmail, Chat andamp; File standardsWeb andamp; Chat protocolsXML andamp; JSON schemaLDIFTLS server/cli