John Meletis

John Meletis is a seasoned professional with extensive experience in customer success, service delivery, and systems engineering. Currently serving as the Global Customer Success Strategy Director at Mastercard since November 2025, John is responsible for defining and scaling global strategies to enhance customer value. Prior to this role, John held various positions at Microsoft from 2016 to 2020, including Services Business Manager and Regional Customer Success Account Management Director, focusing on operational excellence and customer-centric strategies. Earlier experience includes a role as a System Engineer at NBG, managing SQL servers and PKI infrastructure, and as an ITS SSP at IBM, where John implemented solutions at customer sites and improved customer relations. John holds a BSc in Physics from Ethnikon kai Kapodistriakon Panepistimion Athinon and completed secondary education at 2nd High School Argiroupolis.