This book constitutes the refereed proceedings of the 15th Software Quality Days Conference, SWQD 2023, held in Munich, Germany, during May 23-25, 2023. The Software Quality Days (SWQD) conference started in 2009 and has grown to the biggest conference on software quality in Europe. The program of the SWQD conference is designed to encompass a stimulating mixture of practical presentations and new research topics in scientific presentations. The guiding conference topic of the SWQD 2023 is “Higher Software Quality through Zero Waste Development”. The 4 full papers and 2 short papers presented in this volume were carefully reviewed and selected from 10 submissions. The volume also contains one invited talk.