This book constitutes the refereed proceedings of the 11th International Conference on Networked Systems, NETYS 2023, held in Benguerir, Morocco, during May 22-24, 2023. The 9 full papers and 3 short papers presented were carefully reviewed and selected from 31 submissions. The scope of the conference covers all aspects related to the design and the development of these systems, including, e.g., cloud systems, formal verification, concurrent and distributed algorithms, data management, data science, parallel/concurrent/distributed programming, machine learning, multi-core...