Our client, a leading global multinational information technology services and consulting company, is recruiting aMobile Core / IMS Support Engineer (VoLTE)to join their business inSpain.Position Title: Mobile Core / IMS Support Engineer (VoLTE)Position Type: Permanent or FreelancerStart Date: ASAPLocation: Madrid, SpainContact: Franci | +49 89 23 88 98 55Responsibilities:Support and executedeployment projectsfor new solutions and platforms. Participate inexpansions, upgrades, and evolutionsof existing customer projects. Providepost-sales technical supportfor production platforms and services. Analyze, troubleshoot, and resolvetechnical incidents. Escalate and follow up complex technical issues until full resolution. Coordinate with internal teams, customers, vendors, and other technical stakeholders. Prepare and maintain technical documentation, procedures, and reports. Participate in anon-call / standby support scheme, depending on service needs. Provide remote support and, when required, support planned interventions or emergency activities.Requirements:The candidate must have strong experience in one or more of the following domains:Value Added Services (VAS) – SMSC / IN Strong experience with Value Added Services platforms, particularly SMSC and Intelligent Network (IN) environments. Proven experience in integration, deployment, configuration, and operational support of SMS and IN service platforms. Solid understanding of SMS service architecture, routing, and interworking within mobile networks. Experience in service provisioning, troubleshooting, and performance analysis in VAS environments. Knowledge of signaling protocols related to messaging and IN services (e.g., SS7/MAP, SMPP, Diameter).Mobile Core (2G3G4G5G) – Packet Core and IMS (VoLTE / VoWiFi) Strong technical and functional knowledge ofMobile Core networks, with focus onPacket Switched (PS) Core and IMS-based services. Experience withFixed and Mobile IMS architectures, includingVoLTE and VoWiFi service implementation and support. Proven experience inintegration, deployment, upgrades, and operational supportof core network nodes. Good understanding ofIMS signaling and protocols(e.g., SIP, Diameter) andend-to-end service flows. Strongtroubleshooting capabilities across mobile core and IMS environments .Language Requirements Fluent Spanish and English are mandatory.