"Software Design Principles" is $4. Amazon claims it is 72 pages. The pdf is 50 pages and minus the front/back matter, there are a little under 40 pages of content. Which is fine for a $4 e-book, but quite misleading. It also irks me that the title of the book is in all capitals on Amazon as that feels like shouting on the internet. But on to the actual content:
Some principles are described at length. Others are barely mentioned with only a sentence or two of description. Continuous integration has one paragraph (5 sentences), but it feels like the principle is barely touched on.
I really liked the "synthesis" table which shows graphically how principles go together. And the descriptions are fine. Some of them are quite thorough in fact.
My biggest problem with the book is that I feel like it covers too much for a 40 page book. In that way, it servers more as "here is an overview of some topics you might want to read more about elsewhere." The author says that he inserts his own experiences throughout the book. I only counted 4 such instances. He also says the book can serve as both a tutorial and a reference. I agree on the reference part. I agree that it can be used as "cheat sheet." I disagree that it is comprehensive enough to cover "even the edge concepts."
I also think the target audience is too broad. A software architect should know this material by now. Although I suppose it could serve as a review. And I think a junior developer would require more elaboration.
That said, the book only costs 4 bucks. It's worth buying just as an outline or a list of things to learn more about after you have gotten the overview. I think I was most bothered by the implication that the book was longer.
Disclosure: I received a copy of this book from the publisher in exchange for writing this review on behalf of CodeRanch.