This book PSE 15584 constitutes the refereed proceedings of the 6th International School on Engineering Trustworthy Software Systems, SETSS 2024, held in Chongqing, China, in April 14-21, 2024. The 5 full papers and 2 short papers were carefully reviewed and selected from 7 submissions. The proceedings focuses on -Preparatory Course: Introduction to Mathematical Logic and Logic of Programming; -Introduction to Digital Twins -Theories of Contracts and Their Applications -From Automata Models to Validated BCI-Based Cooperative Control On the Viability of Rigorous Approaches to Human-Cyber-Physical Systems of Systems; What Came First, Math or Computing? -What Came First, Math or Computing? -Software Engineering for Explainable AI -Distribution Testing: The New Frontier for Formal Methods.