This volume constitutes short papers and DEITS 2023 workshop papers, presented during the 12th International Conference on Model and Data Engineering, MEDI 2023, held in Sousse, Tunisia, in November 2023. The 12 short papers presented were selected from the total of 99 submissions. This volume also contains the 7 accepted papers from the DEITS 2023 workshop, held at MEDI 2023. The volume focuses on machine learning and optimization; natural language processing; modeling and data management; healthcare applications; data engineering in IoT systems. .