A Philosophy of Software Design, 2nd Edition

One of the best books about Software Engineering that I've read so far. The book is very clear and concise. It's written so well with easy-to-understand examples, I'm in my early career but can easily capture the author's ideas. This book mainly discusses about the "Complexity". Not the time nor the space complexity in algorithm but the complexity of human understanding the codebase. This book guides me how to produce good code and identify the bad code . If you're a software engineer who loves writting beautiful code, this book will be worth every second. Additionally, I love the list summary at the end of the book. It helps me review the key design principles and red-flags one more time before I put this book down

Since 2016, my job has been to teach software design at the advanced level to professional engineers. I run workshops, speak at tech companies, and blog on software design. So when I heard of this book, I naturally took a look to see if I could recommend it to students. PoSD is best read as a tactical guide of how-to’s. About a quarter of it is spent on naming and comments, and much of the rest is about specific patterns. His few attempts to jump from tactical advice to principles are either done by trying to blur together similar-sounding tips, or are hamstrung by his inability to see the meaning of a program beyond the code. He demonstrates the lack of principles comically in Chapter 19, where he promises to apply the books’ “principles” to several software trends, and then fills the rest of the chapter with standard (but solid) advice on unit-testing and OOP, with nary a reference to the rest of the book. On the whole, the book’s advice is higher-level than beginner books like Clean Code, but most of its contents will be familiar to a senior software engineer, and the novel parts are hit-and-miss. A huge underlying theme of the book, and one of its few novel parts, is Ousterhout's idea of deep modules: modules should have an implementation which is simpler than the interface. This sounds elegant, and impossible to argue with. Unfortunately, it's also objectively wrong. Further inspection shows that actually many common abstractions like stacks fail this test, and even Ousterhout's own example of a deep module has an interface which is far more complex than he claims. Overall, Ousterhout misses the deeper notions of complexity, the kind which is about what a piece of code means and how it may be used and how it may be changed, rather than the kind that can be gleaned by glancing at the code. This is a major blindspot which damages the book significantly, and limits his ability to give precise advice. When Ousterhout tells you do reduce complexity, it often sounds like telling someone going on a date or interview "just be yourself:" the advice only works if you already understand complexity. Despite that, there is a lot of really good advice in this book, and it's explained with clear and concrete examples. I especially enjoyed his sections on comments. While I don't agree with everything in that section either, there are some really good points that I hope become common practice, and which I have not seen others write about. His chapter on performance engineering is also gold. So, read the book, savor the advice, but take his justifications with a grain of salt and know that they're not universals, because there are deeper principles to be found. I wrote a much longer review on my blog, going into these points in more detail. For my full review, see: http://www.pathsensitive.com/2018/10/book-review-philosophy-of-software.html A Philosophy of Software Design is a good book, but not a great one. But it's one of the only books of its kind out there. Hence, I am proud to recommend it to all junior-level software engineers.

I think every person who has written a fair amount of code should read this book. Managers should buy it for their teams. It should be required reading for new team members (it doesn't long to get through - a few hours). It is NOT for beginner programmers in my mind - you will not have written enough code to understand the points being made. I'd say it's perfect for mid-level to advanced programmers. Why for advanced? Because they can quickly get throught it, and challenge some of their own design assumptions and practices. Mid-level programmers will find it a treasure. The title of the book is perfect, because it really is more philosophical and high-level. But that doesn't mean it's abstract nor boring. I find the ideas very applicable and easy to understand. The opening statements are very powerful - what is complexity, the difference kinds of complexity ("cognitive load" is an excellent concept), etc. It ends with a gem - you know your code is complex if you end up spending a lot of time fixing bugs in it. Complexity begets complexity. Don't let the critical reviews stop you from reading this book - so what, it ignores functional programming. Readers can buy books on that and contrast the desgin philosphy. Yes, it's OOP-based, but so what? It's easy to apply these ideas to non-OOP languages or concepts. Some complained about "3 chapters on comments alone". Not true - the three chapters cover different subjects, and provide excellent guidelines for commenting first (designing with your comments - kind of like writing a mini-spec, if you will), what constitutes a useful comment, and how to name variables. I found it very useful. The concept of "deep" versus "shallow" classes is very interesting, even if some of the reviews have criticized it. The author provdes a very nice clue to whether or not code should be broken out - do you have to keep flipping back and forth between the sub-task and the original function? Maybe it shouldn't have been broken out. Deep classes have simple interfaces and accomplish a lot for the caller. Shallow classes, on the other hand, require the caller to know about them, how to call them in order, etc. Good stuff. It's a short read. You'll scarcely find a book that's so short be so valuable. You can get through it in about 3-4 intense, focused sessions.

This book is clear, concise, and avoids padding for the sake of page count. This mirrors how the author advocates that software should be designed: minimize complexity, and pursue simplicity. The book lays out many strategies to achieve this goal, while also explaining how one approach reinforces and strengthens another. I found some of the examples to feel a bit academic, yet most do a good job of clarifying the concept being supported. The author has also offered rebuttals for many of the common reasons developers underinvest in software design, which hopefully helps readers confront their internalized self-bargaining techniques (some of which can be seen by reading other reviews here). My primary criticism is that I had hoped for a chapter or two about how to approach a poorly designed system and move it toward a clean design. There's really only a few spots where even needing to make a trade-off like this is recognized, and the most prominent ends with the proposed solution being to ship the feature on the deadline and ask for refactor time in the future. This almost never happens, since there's always another deadline on the horizon. Another place where the problem is briefly acknowledged makes the argument to always leave code with a better design than it was found in. This isn't always possible, however, as sometimes it's necessary to build iteratively around poor design (violating the consistency and complexity principles) before being able to eliminate it. In other words, on a large system, it's sometimes necessary to make a mess even messier before you can clean it up. I'd love to read the author's perspective on this facet of software design, and how to reason through such trade-offs. That said, given that my main critique is that I'd like to hear even more from the author on the topic of software design, I can easily recommend this book to every professional, or aspiring, software engineer. For more senior folks, it'll likely be a crystallization of wisdom you've already learned, in a form that'll be easier for you to socialize with the rest of your team. I, for one, would love to work on any team where the contents of this book are really internalized and applied.

The best software design book. I used to recommend Clean Code but the approach detailed here on when to break apart methods/functions is superior and avoids unnecessary (and therefore harmful) abstraction.

I was interested to read a book which titled itself as a philosophy of software design. I was disappointed to find nothing more than the well worn and trodden path of oo software advice, some of which is a little dated. Seems like a good thing to teach to the students in these courses, but calling this a philosophy is too far of a stretch. All in all, the principles are exactly what you would learn in your cs education, and most of them are a good place to start. Nothing here for the advanced engineer.

Writing computer code provides a programmer incredible freedom, but writing good code that'll work in a team environment is a trickier assignment. Many coders fall back on whatever guidelines their manager issues, but that approach can obscure the real challenge. Not only is someone programming a computer to achieve a certain goal, but that person is simultaneously writing a letter to their future self and fellow programmers about what they are trying to do. Clear communication is as much a part of the challenge as getting the code to work in a maintainable fashion. In this book, John Ousterhout of Stanford University guides newer and mid-career programmers how to write better code. Computer programmers can be famously inflexible with personal coding standards. Whether one agrees with Ousterhout on ever issue or not - I certainly didn't - reading about others' understanding of coding increases your tolerance of other programmers. It simply makes you a better teammate. We all need better teammates, and it starts with you and me personally. He hits on all the major issues good programmers talk about with each other: when to write comments, how to construct self-documenting code, how to design deeply effective classes, and more. These are not challenges that are mastered once-and-for-all; rather, they are daily challenges with each programming assignment. Even as someone who has been programming for decades, he helped me see my craft in small, new ways. The obvious market for a book like this are newer and mid-career programmers. But advanced programmers often benefit from reviewing the main themes from a master craftsperson; indeed, at the very least, they can learn how to express themselves to their mentees. I slowly skimmed this book but slowed down for thoughts that I may not have had explored before. Coders of every ilk like learning by doing, but learning-by-doing has to be supplemented by coaching. Most supervisors don't have the time to do that in depth, so reading books about coding becomes essential. This one should certainly be on the reading list.

This book is comprised of short, easy-to-read chapters on what the author believes are proper software design practices, primarily for the C/C++ and Java languages. Most of the design practices are relevant for other languages and methodologies (functional, procedural, etc.) as well. Whether or not you agree with those practices is another question, and based primarily on which coding style camp you fall into. If you're a firm believer in Agile practices, test driven development, self-documenting code, or the latest coding standard fads you will likely take issue with this book. For example, the author prefers 'strategic' software design over 'tactical' design. The former means thinking about where the system is going and writing code that is maintainable and extensible over the long haul, as opposed to the 'tactical' approach of getting a minimal something running as soon as possible. Of course, such advice conflicts with modern practices such as Agile and associated software philosophies such as YAGNI (You Ain't Gonna Need It). If you agree with the author (as I do) and don't care much for some of these 'modern' ideas you'll love this book. On the other hand, if you live and breathe Extreme Programming, code in JavaScript, and believe that any program that takes more than two weeks to write will miss the market window, well, you won't find much to agree with here. To be fair, I have 40 years of experience in writing software for embedded systems, mostly in C/C++. There really wasn't much in this book that I didn't already know and practice. Like the author, I'm a firm believer in code with lots of well-written comments that document WHY (and not what) the code is doing. Like the author, I find test-driven development clumsy and ineffective. Like the author, I believe that simple interfaces and deep implementations are important, and that small function bodies create bloated, overly-complicated programs with a tendency toward "classitis" (the authors term for too many small classes). In other words, the author's biases match mine, and we both write code in software fields where the languages, tools and targets favor methodical, efficient, maintainable, and extensible code bases. I love this book. A developer writing a front-end for a cloud-based app using a framework-based language, where time-to-market is everything, probably won't. I recommend this book highly for software engineers who would like to take a break from the latest coding practice du jour and write well-crafted, easily maintainable code for a change.

「ソフトウェアの複雑性を下げる」は、設計の主要な目標ですが、これについて簡潔に包括的に書かれた本です。 深い(浅い)モジュール/名前の横断性/コメント規約/情報隠蔽(漏洩)など、古い設計手法も新しい視点で書かれています。 Linterや計測ツールを作りたくなりました。

Excelente

Possibly my favourite tech book ever. Unlike other "clean code" books, it's not just a collection of advice, it unfolds a real theoretical framework that embodies the perks it touts in good design: simplicity, concision, consistency and pragmatism. It felt like the author somehow found just the right abstractions to describe what we pursue in good code. All served by spot on mental models (deep modules, information leakage), simple yet precise language and telling examples.

It's an amazing book where you get insights about how to build and maintain a software design. It's technical, but not a heavy reading, which makes it even more enjoyable.

The book's examples are mostly from programs running on an OS, with significant iron underneath. I mostly work with embedded systems, which are severely resource contained, often running on bare metal with a limited thread scheduler. Still, I found the book being generic enough to be applicable for that niche as well. I completely agree with Prof Ousterhout regarding shallow methods, variable duplication and the like being red flags. He repeatedly re-iterates the importance of hiding implementation details, which is actually one of the stated goals of OOP, The book tries to drive a point through: your system's long-term manageability depends on its abstractions, how you partition the task at hand into self-contained chunks with minimum, or preferably no interdependence between them. Yes, it cost a a lot of design time without cranking out any code, but this investment will be paid back during the actual implementation, and, more importantly, during the lifetime of the project (which with embedded systems is often decades). I especially like his talking about commenting the code and how comments provide meta-information that the code does not convey. The code should be obvious, sure. You read it and should know what it does. But will you know why it does it the way it does? Often the code is written on a particular way to accommodate peculiarities of the underlying hardware, and it incorporates a lot of knowledge/mathematics of a completely different field that the device services. You might have it all in your head when working on the project, but expecting the next guy (or even yourself a few years later) to know it all is not realistic. Comments can point out all those externalities and provide a rational for particular, possibly counter-intuitive, design choices employed in the code. Overall, I think the book is an eye-opener, at least it should make you think about abstractions, interactions, separation, generalisation, and, the most important message of the book, minimising complexity.