The book "Engineering Secure Software and Systems" documents the proceedings of the Second International Symposium on the Development of Secure Software and Systems. This event brought together professionals from the fields of software and security engineering to promote the exchange and advancement of both disciplines. The collaboration with ACM SIGSAC and ACM SIGSOF highlights the relevance of this interdisciplinary research area. Today, the challenge of building secure software systems is no longer limited to mastering security technologies such as cryptography or access control models. Instead, the complexity of modern interconnected software systems, the unpredictability of development cycles, and the interactions between functionality, security, and other quality attributes play a crucial role. The book provides insights into current research approaches and challenges in this dynamic field.