Contract Senior Middleware Engineer required for a 6-month engagement (Inside IR35 via Umbrella) to support a large migration programme moving legacy SLES and Oracle Linux environments to Red Hat Enterprise Linux (RHEL) on GCVE. Key responsibilities include installing and configuring middleware (IBM MQ, WebSphere ND/Liberty, IHS, WebSphere Portal), deploying applications, performance tuning and automation, monitoring with AppDynamics/Wily/Tivoli, security management (SSL/TLS, certificates, OAM), and collaborating with cross-functional teams across 30+ projects within a 60-person delivery portfolio.