This book constitutes the refereed post—conference proceedings of the 10th International Conference on Big Data Technologies and Applications, BDTA 2020, and the 13th International Conference on Wireless Internet, WiCON 2020, held in December 2020. Due to COVID—19 pandemic the conference was held virtually. The 9 full papers of BDTA 2020 were selected from 22 submissions and present all big data technologies, such as storage, search and management. WiCON 2020 received 18 paper submissions and after the reviewing process 5 papers were accepted. The main topics include wireless and communicating networks, wireless communication security, green wireless network architectures and IoT based applications.