This book constitutes the refereed proceedings of the 18th International Symposium on Search-Based Software Engineering, SSBSE 2026, held in Montreal, QC, Canada, during July 2026.The 5 full papers, with 10 short papers included, in these proceedings were carefully reviewed and selected from 23 submissions. The symposium featured four tracks: the Research Track, the SBSE Challenge Track, the Hot-off-the-Press (HOP) Track, and the Replications, Negative Results, and New Ideas...

This volume constitutes the proceedings of 31st International Conference on Cooperative Information Systems, CoopIS 2025, held in Marbella, Spain, during October 20–22, 2025.The 24 full papers and 21 short papers included in this book were carefully reviewed and selected from 128 submissions. They were organized in topical sections as follows: Invited Speakers; Data-Driven and Predictive Process Analytics; Neuro-Symbolic Systems and Knowledge Graphs; Process Conformance, Integrity ...