That was one of "the" books in the space prior to DDIA. In my opinion Akidao mixes the logic for processing events with the stream infrastructure implementation because he was writing from the context of his particular use cases. The time that I spoke with him it seemed that his influence had driven to the design of Google's systems and GCP such that they didn't properly prioritize ordering/linearity/consistency requirements. At this point my copy is of historic interest to me.