Theodoros Gerostergioudis joined Diamantis Masoutis S.A. in September 2021 as Chief Operating Officer and subsequently appointed as Member of the Board implementing a unique strategic growth program. Diamantis Masoutis S.A. is one of the largest grocery retailers in Greece with more than 400 stores and turnover of 1.2billion. In March 2025, Mr. Gerostergioudis was elected as Retail Chairman of the ECR Hellas.
Previously, he was working as Director in KPMG London and has extensive experience in audit and business consulting, working with several companies across various sectors with expertise in mergers & acquisitions, operations & finance consulting, digital & technology.