This book compiles the research findings presented at the 4th International Conference on Novel & Intelligent Digital Systems (NiDS 2024), which took place in Athens, Greece, on September 25-27, 2024, hosted by the University of West Attica. NiDS 2024 was conducted in a hybrid format, offering participants the flexibility to join either online or in person. The conference highlighted the latest innovations in intelligent systems and emphasized the collaborative research that advances Artificial Intelligence (AI) in software development. It served as a platform for high-quality research, providing a space to explore challenges and innovations in AI. NiDS 2024 refered to experts, researchers, and scholars in artificial and computational intelligence, as well as the broader field of computer science, offering insights into interconnected and complementary areas. By promoting the exchange of ideas, the conference aimed to strengthen and expand the network of researchers, academics, and industry professionals.