This volume presents selected peer-reviewed contributions from the XX International Multi-disciplinary Congress on Science and Technology (ESPE CIT 2025), held on-site at the Universidad de las Fuerzas Armadas ESPE from August 11 to 15, 2025. The third volume focuses on Defense Engineering; Innovation, Technology and Society; and Managing Technology and Sustained Innovation, bringing together both theoretical and applied research. The contributions cover a broad range of topics within security and defense, exact sciences, human and social sciences, and economic and administrative sciences. The studies reflect scientific rigor, interdisciplinary collaboration, and a strong commitment to advancing knowledge and addressing contemporary technological and societal challenges.