This book constitutes the thoroughly refereed post-workshop proceedings of the 19th International Conference on Web Engineering, ICWE 2019, held in Daejeon, South Korea, in June 2019. The 11 revised full papers were selected from 25 submissions. The workshops complement the main conference and explore new trends on core topics of Web engineering and provide an open discussion space combining solid theory work with practical on-the-field experience. The workshop committee accepted three workshops for publication in this volume: 5th International Workshop on Knowledge Discovery on the Web (KDWEB 2019), Second International Workshop on Maturity of Web Engineering Practices (MATWEP 2019), International Workshop on Data Science and Knowledge Graph (DSKG 2019).