NATO FAS Application & Wintel Support Engineer Location: Portsmouth (On-site) Rate: Up to £500 per day Contract: Contract Clearance: Active UK DV Clearance - Essential Role Overview We are seeking an experienced NATO FAS Application & Wintel Support Engineer to provide technical support and infrastructure services within a secure Defence environment in Portsmouth. The successful candidate will have a strong background in Windows infrastructure, virtualisation and application support, ideally with previous experience supporting NATO Federated Applications and military operational environments. You will be responsible for maintaining, supporting and troubleshooting critical applications and their underlying infrastructure, ensuring service availability and operational effectiveness across secure networks. Key Responsibilities Provide 3rd and 4th line application and infrastructure support within a secure Defence environment. Support and maintain NATO FAS applications across Windows and Linux-based environments. Administer and troubleshoot Windows Server, Active Directory and associated Wintel technologies. Support virtualised infrastructure using VMware, vSphere, vCenter and Hyper-V. Investigate and resolve complex application, server and infrastructure incidents. Support application deployments, upgrades, configuration and integration activities. Provide technical support during NATO exercises and operational deployments. Troubleshoot connectivity, authentication and application performance issues across secure networks. Maintain technical documentation, operating procedures and configuration records. Work closely with infrastructure, application and service delivery teams to maintain operational capability. Technical Skills & Experience Essential: Strong Windows Server and Wintel infrastructure experience. Experience supporting enterprise applications within secure environments. Active Directory administration and troubleshooting. VMware / vSphere / vCenter or Hyper-V experience. 3rd / 4th line technical support and complex incident resolution. Experience working within Defence, Government or military environments. Active UK DV Security Clearance. Desirable: Previous experience supporting NATO Federated Applications (NATO FAS). Knowledge of applications such as ICC, NIRIS, Openfire, TOPFAS, LOGFAS, JTS, JOCWatch, ArcGIS, SitaWare or iGeoSIT. Experience supporting NATO or MOD operational networks. Windows and Linux application hosting environments. PowerShell scripting and automation. SQL / PostgreSQL and application database support. Experience supporting military exercises and deployed operational systems. Contract Details Location: Portsmouth - predominantly on-site. Rate: Up to £500 per day. Clearance: Active UK DV Clearance is essential. Engagement: Contract opportunity. This is an excellent opportunity for a DV-cleared engineer with a combination of Wintel infrastructure and application support experience to work on critical NATO Defence systems