SBA are supporting our Telecommunication client, who are seeking an experienced Mobile Core Signalling Designer to support a major transformation programme across their Voice Core and Subscriber Data Management estate on an initial 6 month contract located in Reading (hybrid). The ideal candidate will have deep expertise in Ericsson signalling platforms and Nokia SDM, with hands-on experience designing migrations, integrations, and service deployments within mobile core architecture. This is a specialist technical role requiring genuine design experience Essential Technical Skills Ericsson Platforms (must have): DSC IPSTP HLR HSS Nokia Platforms (must have): Nokia SDM experience VNF and/or CNF experience (either acceptable) Exposure to subscriber migration (vendor-to-vendor or like-for-like) General Core Competencies Strong signalling knowledge Diameter routing & signalling protocols Core network design experience Traffic migration & integration design Ability to independently produce reliable HLD/LLD artefacts To apply, please submit latest CV