This book constitutes the refereed proceedings of the 12th Conference on Information Technology and its Applications, CITA 2023, taking place on July 28-29, 2023 in Da Nang City, the most beautiful and livable city in Vietnam. CITA is an annual scientific conference on information technology and its applications in all fields. The main objective of the conference is to create a forum to gather and connect Vietnamese and international researchers, scientists in the fields of information technology and its applications. The book includes 33 papers, selected from 144 papers submitted to CITA 2023 whose authors come from over 20 countries around the world, which were carefully reviewed by at least two members of the Program Committee, with professional advice from reputable scientists in the field of information technology and technology, digital economy such as Prof. Dr.Sc. Ngoc-Thanh Nguyen (Poland), Prof. Dr. Dosam Hwang (Korea), Assoc. Prof. Dr. Le Minh Hoa (UK), and Prof.Dr. Nguyen Thanh Thuy (Vietnam). The acceptance rate of CITA 2023 is about 24%. The papers in the book are organized in the following topical sections: Data Science and Artificial Intelligence; Image and Natural Language Processing; Software Engineering and Information Systems; Network and Communications; and Digital Economy. The accepted and presented papers focus on new trends and challenges facing the information and communication technology as well as digital economy community. If you are scientists, lecturers, doctoral students, we hope that you will find many useful and good quality results from the book for your future research.