This book constitutes the proceedings of the 9th International Conference on Decision Support Systems Technologies, ICDSST 2023, held during May 30 - June 1, 2023.The EWG-DSS series of International Conference on Decision Support System Technology (ICDSST) is planned to consolidate the tradition of annual events organized by the EWG-DSS in offering a platform for European and international DSS communities, comprising the academic and industrial sectors, to present state-of-the-art DSS research and developments, to discuss current challenges that surround decision-making processes, to exchange...