The International Conference on Optimization and Information Systems (COSI) aims to bring together researchers in Computer Science and Applied Mathematics, primarily from the fields of combinatorial optimization, graph theory, information systems, and artificial intelligence. The 18th edition of COSI, to be held in Batna from May 12 to May 14, 2026, will be hosted by the University of Batna 2. This continues the long-standing series of successful conferences previously organized in Tizi-Ouzou (2004), Bejaia (2005),...