This book constitutes of the proceedings from the 28th International Conference on Engineering of Complex Computer Systems, ICECCS 2024, held in Limassol, Cyprus, during June 19-21, 2024. The 18 full papers and 4 short papers presented here were carefully reviewed and selected from 68 submissions. These papers have been categorized into the following sections: Machine Learning and Complex Systems; Neural Network Verification; A.I. for Software Engineering; Smart Contract; Formal Methods; Security & Program Analysis.