Klaus Haeuptle is a developer, trainer, and product owner for engineering topics. During his career at SAP, he has worked as a developer on several products based on various technologies. Additionally, he facilitates communities across SAP with the intention of sharing knowledge and improving practices and tools. He has influenced testing improvements for ABAP, SAP HANA, and SAPUI5. Together with Florian Hoffmann, he wrote an internal Clean ABAP guide, which was later published externally as an open-source project and serves as the foundation for this book.