On behalf of the JCSSE 2024 organizing committee, I am delighted to welcome you to Phuket for the 21st International Joint Conference on Computer Science and Software Engineering. After 20 years, JCSSE continues to be a leading computer science and software engineering conference, where researchers, practitioners, and educators come together to present, discuss, and debate the most recent research results, innovations, trends, and concerns in the field. The main conference is preceded by four days of 30 sessions, including regular paper sessions, poster sessions, invited speaker sessions, and keynote sessions.