This book presents the research contributions from the 5th International Conference on Novel and Intelligent Digital Systems (NiDS 2025), held in Athens, Greece, on September 24–26, 2025, and hosted by the University of West Attica. Continuing the success of previous editions, NiDS 2025 embraced a hybrid format, enabling global participation both onsite and online.

The conference focused on cutting-edge developments in intelligent and adaptive digital systems, with particular emphasis on the role of Artificial Intelligence (AI) and its transformative impact on software engineering, digital applications, and human-centered technologies. NiDS 2025 provided a high-impact platform for scholars, researchers, and practitioners to present original research, exchange ideas, and engage in dialogue across a wide range of disciplines—from computational intelligence and data science to smart systems and emerging digital infrastructures.

By fostering interdisciplinary collaboration, NiDS 2025 strengthened global research networks and promoted innovation that bridges academia and industry. This collection is a valuable resource for those interested in the future of intelligent digital systems and the evolving challenges of AI-driven development.