The fourteen-volume set LNCS 15886-15899 constitutes the papers of several workshops which were held in conjunction with the 25th International Conference on Computational Science and Its Applications, ICCSA 2025, held in Istanbul, Turkey, during June 30–July 3, 2025.. The 362 full papers, 37 short papers and 2 PHD showcase included in this book were carefully reviewed and selected from 1043 submissions. In addition, the conference consisted of 58 workshops, focusing on very topical issues of importance to science, technology and society: from new mathematical approaches for solving complex computational systems, to information and knowledge in the Internet of Things, new statistical and optimization methods, several Artificial Intelligence approaches, sustainability issues, smart cities and related technologies.