Klaus Haeuptle is a developer and trainer 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 was published externally as an open source project and is the foundation for this book.