Clean Architecture is the latest book in the Clean […] series, following Clean Code, and The Clean Coder written by the Software Craftsman Robert C. "Uncle Bob" Martin who most recently became an outcast of the worldwide Software Crafters Community for opinions he expressed in his personal blog regarding diversity.
In the book we are spared from his personal opinions, and only slightly confronted with a tiny dose of everyday sexism, and another big portion of "Uncle Bob has seen it all" in the 50 page Appendix on Architecture Archaeology in which Martin uncovers stories about his work dating back to the early 70s which merely serves to support the validity of the ideas and concepts that have been presented in the previous chapters. It reads like another attempt to infuse Martin's legend with substance, which is odd, since he spent the Preface and Introduction chapters on this topic already.
What I liked about the book is his attempt to guide the reader through techniques and principles that lead to good architecture but also provide a slightly superficial explanation of these topics. He debunks object-operation and is able to reveal the core principles of every software and what good architecture should enable:
good architecture makes software easy to change
and easy to change means that the cost of change is magnitudes lower than the value the change provides. His concepts are designed to enable a very long software lifetime by keeping developer productivity high of years into a software project.
For me personally there weren't any new revelations to be discovered but I liked Martin's way to re-define and sharpen existing ideas using simple language. The chapters surf just below the surface and never dive too deep, which will be problem for unexperienced software developers and architects since they will most likely not be able to connect the dots.
what matters is the domain
I especially like Part IV of the book in where Martin stresses the idea that good architecture abstracts away concrete implementations from the beginning. This idea has been presented in the previous chapters already with a focus on implementation on the module level. Part IV makes this idea more tangible by explaining why and how secondary components (I'd call them that) like databases, UI and frameworks should be separated from the software core.
By page 210 you have already encountered all there is to know in the book so don't be taken away away by the page count. The remaining chapters flesh out the main idea:
Write high-level abstractions for everything that is not your core business domain, and don't let secondary component concepts leak into your business domain.
Despite its excess Uncle Bob Grandeur and idiotic and pointless cartoons I would recommend this book to experienced architects and software developers since it reinforces and clarifies proven concepts, which I am using on a daily basis.