Category: Continuous Learning

Book review: A Philosophy of Software Design

This blog entry is structured in two main parts: The prologue sets the tone, but may be irritating because it doesn’t talk about the book itself. If you get irritated or know the topic well enough to skip it, you can jump to the second part when I talk about the book. It is indicated by a TL;DR summary of the prologue.

Prologue

Imagine a world where the last 25 years of computer game development didn’t happen. A world where we get the power of 5 GHz octacore computers and 128 GB of RAM, but nobody thought about 3D graphics or interaction design. The graphics of computer games is so rudimentary, it consists of ASCII art and color. In this world, two brothers develop a game that simulates a whole fantasy world with all details, in three dimensions. The game is an instant blockbuster hit and spawns multiple cinematic adaptions.
This world never happened. The only thing that seems to be from this world is the game itself: Dwarf Fortress. An ASCII art sandbox simulation of a bunch of dwarves that dig into the (three-dimensional) mountains and inevitably discover the fun in magma. Dwarf Fortress is a game told by stories, not graphics. It burdens the player to micro-manage a whole settlement down to the individual sock – Yes, no plural. There are left socks and right socks and they are different entities with a different story. Dwarves can literally go mad because they miss their favorite left sock and you didn’t notice in time. And you have to control all aspects of the settlement not by direct order, but by giving hints and suggestions through an user interface that is a game of riddles on its own.
Dwarf Fortress is an impossible game. It seems so out of time and touch with current gaming reality that you can only shake your head on first contact. But, it is incredibly deep and well-designed and, most surprising, provides the kind player with endless fun. This game actually works!

TL;DR: Just because something seems odd at first contact doesn’t mean it cannot work. Go and play Dwarf Fortress!

The book

John Ousterhout is a professor teaching software design at the Stanford university and writes software for decades now. In 1988, he invented the Tcl programming language. He got a lot of awards, including the Grace Murray Hopper Award. You can say that he knows what he’s doing and what he talks about. In 2018, he wrote a book with the title “A Philosophy of Software Design”. This book is a peculiar gem besides titles with a similar topic.

Imagine a world where the last 20 years of software development books didn’t happen. One man creates software for his whole life and writes down his thoughts and insights, structured in tactical advices, strategic approaches and an overarching philosophy. He has to invent some new vocabulary to express his ideas. He talks about how he performs programming – and it is nothing like today’s mainstream. In fact, it is sometimes the exact opposite of today’s best practices. But, it is incredibly insightful and well-structured and, most surprising, provides the kind developer with endless fun. Okay, I admit, the latter part of the previous sentence was speculative.

This is a book that seems a bit out of touch with today’s mainstream doctrine – and that’s a good thing. The book begins by defining some vocabulary, like the notion of complexity or the concept of deepness. That is rare by itself, most books just use established words to deliver a message. If you think about the definitions, they will probably enrich your perception of software design. They enriched mine, and I talk about software design to students for nearly twenty years now.

The most obvious thing that is different from other books with similar content: Most other books talk about behaviours, best practices and advices. Then they throw a buch of prohibitions in the mix. This isn’t wrong, but it’s “just” anecdotal knowledge. It is your job as the reader to discern between things that may have worked in the past, but are outdated and things that will continue to work in the future. The real question is left unanswered: Why is it so?

“A Philosophy of Software Design” begins by answering the “why” question. If you want to build an hierarchy of book wisdom depth, this might serve as one:

  • Tactical wisdom: What should be done? Most beginner’s books work on this level. They show exactly what goes on, but go easy on the bigger questions.
  • Strategic wisdom: How should it be done? This is the level that the majority of good software design books work on. They give insights about your work ethics and principles you should abide by.
  • Philosphical wisdom: Why should it be done? The reviewed book begins on this level. It explains the aspects of software and sourcecode that work against human perception and understanding and shows ways to avoid or at least diminish those aspects.

The book doesn’t stay on the philosophical level for long and dives deep into the “how” and “what” areas later on. But it does so with the background of an established “why”. And that’s a great reminder that even if you disagree with a specific “what” (or “how”), you should think about the root cause of your disagreement, not just anecdotes.

The author and the book aren’t as out-of-touch with current software development reality as you might think. There is a whole chapter addressed to current “software trends” like agile development and unit tests. It has a total page count of six pages and doesn’t go into details. But it at least mentions the things it doesn’t talk about.

Conclusion

My biggest learning point from the book for my personal habits as a developer is to write more code comments in the way the book proposes. Yes, you’ve read that right. The book urges you to write more comments – but good ones. It talks about why you should write more comments. It gives you extensive guidelines as to how good comments are written and some examples what these comments look like. After two decades of “write more (unit) tests!”, the message of “write more comments!” is unique and noteworthy. Perhaps we can improve our tools to better support comments in the same way they improved support for tests in the last years.

Perhaps we cannot solve our problems with the sourcecode by writing more sourcecode (unit tests). Perhaps we need to rely on something different. I will give it a try.

You might want to give the book “A Philosophy of Software Design” a try. It’s worth your time and thoughts.

Book review: “Java by Comparison”

A review of the book “Java by Comparison” that gives any aspiring Java developer a solid understanding what good code looks and feels like.

I need to start this blog entry with a full disclosure: One of the authors of the book I’m writing about contacted me and asked if I could write a review. So I bought the book and read it. Other than that, this review is independent of the book and its authors.

Let me start this review with two types of books that I identified over the years: The first are “toilet books“, denoting books that can be read in small chunks that only need a few minutes each time. This makes it possible to read one chapter at each sitting and still grasp the whole thing.

The second type of books are prequel books, meaning that I wished the book would have been published before I read another book, because it paves the road to its sequel perfectly.

Prequel books

An example for a typical prequel book is “Apprenticeship Patterns” that sets out to help the “aspiring software craftsman” to reach the “journeyman” stage faster. It is a perfect preparation for the classic “The Pragmatic Programmer”, even indicated by its subtitle “From Journeyman to Master”. But the Pragmatic Programmer was published in 1999, whereas the “Apprenticeship Patterns” book wasn’t available until a decade later in 2009.

If you plan to read both books in 2019 (or onwards), read them in the prequel -> sequel order for maximized effect.

Pragmatic books

The book “The Pragmatic Programmer” was not only a groundbreaking work that affected my personal career like no other book since, it also spawned the “Pragmatic Bookshelf”, a publisher that gives authors all over the world the possibility to create software development books that try to convey practical knowledge. In software development, rapid change is inevitable, so books about practical knowledge and specific technologies have a half-life time measured in months, not years or even decades. Nevertheless, the Pragmatic Bookshelf has published at least half a dozen books that I consider timeless classics, like the challenging “Seven Languages in Seven Weeks” by Bruce A. Tate.

A prequel to Refactoring

A more recent publication from the Pragmatic Bookshelf is “Java by Comparison” by Simon Harrer, Jörg Lenhard and Linus Dietz. When I first heard about the book (before the author contacted me), I was intrigued. I categorized it as a “toilet book” with lots of short, rather independent chapters (70 of them, in fact). It fits in this category, so if you search for a book suited for brief idle times like a short commute by tram or bus, put it on your list.

But when I read the book, it dawned on me that this is a perfect prequel book. Only that the sequel was published 20 years ago (yes, you’ve read this right). In 1999, the book “Refactoring” by Martin Fowler established an understanding of “better code” that holds true until today. There was never a second edition – well, until today! Last week, the second edition of “Refactoring” became available. It caters to a younger generation of developers and replaced all Java code with JavaScript.

But what if you are an aspiring Java developer today? Your first steps in the language will be as clumsy as mine were back in 1997. For me, the first “Refactoring” was perfectly timed, because I had eased out most of my quirks and got a kickstart “from journeyman to master” out of it. But what if you are still an apprentice in Java programming? Then you should read “Java by Comparison” as the prequel book to the original “Refactoring”.

The book works by showing you actual Java code and discussing the bad and ugly parts of it. Then it proposes a better solution in actual code – something many software development books omit as an easy exercise for the reader. You will see this pattern again and again: Java code with problems, a review of the code and a revised version of the same code. Each topic is condensed into two pages, making it a perfect 5-minute read (repeated 70 times).

If you read one chapter each morning on your commute to work and another one on your way back, you’ll be sped up from apprentice level to journeyman level in less than two months. And you can apply the knowledge from each chapter in your daily code right away. Imagine you spend your commute with a friendly mentor that shows you actual code (before and after) instead of only dropping wise man’s quotes that tell you what’s wrong but never show you a specific example of “right”.

All topics and chapters in the book are thorougly researched and carefully edited. You can feel that the authors explained each improvement over and over again to their students and you might notice the little hints for further reading. They start small and slow, but speed up and don’t shy away from harder and more complex topics later in the book. You’ll learn about tests, immutability, concurrency and naming (the best part of the book in my opinion) as well as using code and API comments to your advantage and how not to express conditional logic.

Overall, the book provides the solid groundworks for good code. I don’t necessarily agree with all tips and rules, but that is to be expected. It is a collection of guidelines and rules for beginners, and a very good one. Follow these guidelines until you know them by heart, they are the widely accepted common denominator of Java programming and rightfully so. You can reflect, adapt, improve and iterate based on your experience later on. But it is important to start that journey from the “green zone” and this book will show you this green zone in and out.

My younger self would have benefited greatly had this book been around in 1997. It covers the missing gap between your first steps and your first dance in code.

It’s a beginner’s world

According to Robert C. Martin, the number of software developers worldwide doubles every five years. So my advice for the 20+ million beginners in the next five years out there is to read this book right before “Refactoring”. And reading “Refactoring” at least once is a pleasure you owe to yourself.

Books and talks that shaped my mind as a developer

Over the years I’ve read many books and watched many talks but a few stand out (at least for me) that influenced me in my development career.

The inmates are running the asylum by Alan Cooper
This book opened my eyes that I approached software development completely from the wrong standpoint: the software should serve the user not vice versa.

Design Patterns by Erich Gamma et al
Oh others use the same patterns as me and what? you can even talk about it without explaining every detail…

Refactoring by Martin Fowler
This book taught me that you can change the structure and the design of the software without changing its function. Cool.

Inventing on Principle by Bret Victor
Seeing a new way of interacting with your software in development blew my mind. Think WYSIWYG on steroids.

Getting real by 37signals
Getting to the core of what is essential and what really needs to be done in software/product development is laid out here so clear and stripped down that it struck me.

Information visualization by Edward Tufte
Another book which reduces its topic (this time: presenting information) to the core and by this identifying so much unnecessary practice that it hurts.

Start with why by Simon Sinek
Purpose. Why do you develop software? Why do I arrange an UI or the architecture of an application? This is what design is about.

Only openings by Frank Chimero
Do I try to eliminate failures and therefore options or do I leave the possibility to the user to choose…

Web design is 95% typography by Oliver Reichenstein
Concentrate on the main part, the bigger part, the 95%. If you get them right the rest isn’t so important after all.

Discount usability by Jakob Nielsen
Do what you can do with what you have.

Putting toilet books into practice

A toilet book is a book with a special structure that facilitates short-span context-free reading. In this blog post, I’ll recommend some good toilet books for IT topics.

I’m reading a lot of books and based on my profession and interests, my list includes many software development and IT books. I want to share how I manage my reading and give some recommendations for a special type of book that I call “toilet book”.

Three books at once

The human mind is a peculiar thing. You’ve probably experienced the effect of getting up to perform some minor task in an other room only to arrive there with no recollection about what you wanted to do. Between the thoughts of “ok, let’s do this now!” and “why did I go here?”, just a few seconds have passed, but another aspect has changed dramatically: your geographic position. As a side note: If you don’t know what I’m talking about, consider yourself lucky. Our memory is often bound to the geographic position and changes when we move. If you want to remember what your forgotten task was, try returning to your original location. You’ll often see me walking around the same way twice within seconds. That’s when I have to rewind my location-based memory.

A particular use case where I leverage my location-based memory is when I read books. I often read three books at once, but strictly separated by location:

  • The first book is the “leisure book“: I will only read it at comfortable locations like the couch, in the sun on the balcony or in the bathtub. This book is often fiction or has at least nothing to do with IT.
  • The second book is the “travel book“: You’ll seldom see me travelling without a book and just a few minutes of tram are sufficient to read some pages. This book is often IT-based, because I read it on my commute to and from work and sometimes in my lunch break.
  • The third book is the “toilet book“: You’ll never see me reading this book, because it is stored besides my toilet and is exclusively read there. Books that are suitable for this task often have a special structure that aligns with the circumstances. More on this in a moment.

By having a clear separation by location for the three books, I’m able to keep their content separated and switch from one reading context to the next without effort. It happens naturally if I refrain from reading my travel book at home or taking my leisure book on the train.

The structure of a toilet book

A good toilet book has a special structure that accommodates for the special timing of a toilet visit. If you spend two minutes on the toilet, the book should have chapters or at least paragraphs that can be read in two minute intervals. Ideally, the book is specifically designed to contain short chapters on different topics that have no strong over-arching story. A typical example of a good non-IT toilet book are comic books like Calvin & Hobbes, The Peanuts or any other comic series that has small self-contained comic strips. You read one or two strips, are amused and interrupt again without having to memorize a complex context. Good toilet books allow for short, context-free reading sessions.

A collection of worthwhile toilet books

Over the years, I’ve read some toilet books with IT and software development topics and want to share my list of books that I enjoyed reading in this fashion:

In short, for me, calling a book a “toilet book” is not a derogatory taunt, but a neutral description that this book is structured in a way to support repeated short-time reading sessions. For me, these books are a good choice for a tertiary reading track.

A call for proposals

Right now, my reading list of good IT toilet books is rather short. If you happen to know a book that fits my description, I would be thankful for a hint in the comments. Thank you!

Ten books that shaped me as a software developer – Part II (Books 5 to 9)

I was asked what books shaped me as a software developer the most. Here is the second part of my answer.

In the first part of my answer (books 0 to 4), I highlighted five books that influenced my career as a software developer. The list is not ordered, so the next five books aren’t inferior or better than the first ones. Every book on the complete list made a significant contribution to my knowledge and work ethic.

Clean Code

If we were to choose the holy book of software development, we probably couldn’t agree on one or even a dozen titles. And that is a good thing, because there is no one true way of software development. Clean Code by Robert C. Martin would maybe show up in the late contenders. But if we were to choose the most preachy book of software development, well, I have a favorite. This book is so loud that you cannot ignore it. And it is so opinionated that you’re either nodding your head like a heavy metal fan or writhing in averseness. That’s a good thing, too. Because it forces you to think. Your immediate emotional answer needs support by rational arguments and this book will provide you with ample opportunity to gather arguments for your consent or rejection. What this book probably won’t do is leave you unaffected. When it came out in 2008, it was an instant classic. You could spice up any gathering of software developers by making a statement about this book, be it pro or contra. And even today, ten years later, I would say that even if the loudness is deafening, the clarity of the messages makes this book a worthwhile read for every software developer. My grief with it is foremost that for a book called “Clean Code”, some examples of actual code are quite dirty or even plain wrong. Read it with an active mind and it will be a cornerstone of your professional career. But be careful, it seems that currently printed instances have physical quality problems.

Growing Object-Oriented Software, Guided by Tests

Ever since Extreme Programming hit the (european) scene in 1999, I was curious about Test Driven Development (TDD). I tried automated testing and unit tests whenever I could, read books and later watched videos about the topic. But I never grokked it. It just didn’t work for me and I didn’t even know why. My most feared trap was the one-two-everything syndrome, where you write two simple tests and then have to implement the whole algorithm to fulfill the third test. It was always the third test that broke my rhythm. I tried to exchange experience with TDD practitioners, but their own examples were mostly trivial and my examples always led nowhere (for reference: Try a simple Game of Life in TDD style). I felt dumb and inadequate. When Robert C. Martin (the author of Clean Code) told the developer world that you are either “TDD or not professional” (read the original from 2007 behind this paywall or the reprise from 2014 here or, even better, watch this discussion from 2012), that didn’t make me feel exactly great, too. But imagine my surprise when I started to read a book by two authors I hadn’t heard much of before with a title that reveals its intent only after a comma: “Growing Object-Oriented Software, Guided by Tests” (henceforth called the GOOS book). The book spoke clearly to me. Every step was actionable, even more so, the book acted it out right before my eyes. It was as if Steve Freeman and Nat Pryce, the two authors, were sitting left and right at my table and discussing actual code with me. It didn’t help that I read this book during a summer beach holiday. The beach and even the sun didn’t see much of me that year. I was busy learning about Acceptance Test Driven Development (ATDD), ports and adapters and all the other great content in this book. And the best thing was: it wasn’t theoretical, the examples in the books could be followed one a line-to-line basis. My experience with this book was unique and still is. It’s the best book about actual software development that I’ve read. You might enjoy it, too.

Domain Driven Design

Some years after the GOOS experience, another summer beach holiday was due and as usual, I included a software development book in my luggage. “Domain Driven Design” by Eric Evans came out in 2003 and was praised by some and ignored by most, including me. It took me ten years to finally read it and when I did, it hit me hard. Since my early days as a programmer, I tried to build a meaningful data model with actual types for each program I developed. But it occurred to me that I did it half-heartedly all the time. It shouldn’t stop at a data model, it should be a complete domain model. And for that to work, you need to grok the domain. I review a lot of my code before that insight and always find it funny how I invested effort in my models but more often than not stayed in the technical realm. I cannot say that my programming has changed much from the book, as most concepts meandered through the community since 2003 and were picked up by me mostly under different names. But my software development approach has changed dramatically. I don’t start my thinking from the technical side anymore. And that helps with “business alignment” and all the other magic words that finally have real tangible benefit. And I can now pinpoint when that alignment loosens and employ counter-measures instead of ending up in a special case hell. The best thing was that this book doesn’t require a laptop so I got to sit on the beach that summer with the book in my hands and my head in the clouds. It might be old, but it’s still gold.

Clean Architecture

I anxiously waited for this book to be printed. Not because I pre-ordered, but because I held talks, workshops and lectures about the topic before the book was available. And I wanted to make sure that I’m not telling nonsense. But Robert C. Martin took his time and delayed the deadline month after month. Then, nearly a year later, the book reached the stores in late 2017. So I would have to wait for my winter holiday to read it. I couldn’t wait and began right away. The book is a slow burner and feels like a long introduction. By the time the central proposition is revealed (and yes, it reads like good unagitated spy thriller at times), you’ve probably already figured it out yourself. And that’s a good thing in my mind, because it feels as if it was your idea and Uncle Bob is just there to nod and congratulate you for your intellect. This book is so many times less preachy than “Clean Code”. If we compare spy thriller literature, this is a John le Carré while Clean Code would be an Ian Fleming (James Bond). “Clean Architecture” is not about programming, it talks about software architecture, a topic that I missed greatly in my early developer years. I liked this book so much I even wrote a full review about it.

The Inmates Are Running the Asylum

All the other books talk about different aspects of programming, software development or related technical topics. But what about a book that raises a simple question: “Why is IT technology so complicated?”. And gives the answer: “Because we want it this way.”. That’s actually true. In a world without most of the restrictions of the physical world, we were unable to build solutions that actually helped us and came up with machines and software that overwhelmed most people. It needed a whole new generation of “digital natives” until concepts like internal operation modes (e.g. insert vs. overwrite) were intuitively understood. Not because they became simpler, we were just used to the complexity. Alan Cooper described the problem and gave at least hints for solutions in 1999, nearly 20 years ago. That’s the timespan of a generation. This book made me think hard about the status quo I silently had accepted with technology. It just was like it was, what else could there be? If I reveal a tiny bit of different approaches I can think of now, I’m often confronted with incomprehension. Not because I’m particularly clever and everyone else is dumb, but because there seems to be no problem if you’ve grown accustomed to it. If you want to see some of the pain other (older) people feel when interacting with technology and software, read this book. It is an eye-opener to common problems no software developer ever had. It is the first step into the world of UX (user experience), where it’s not as important if the developer feels alright but if the user feels at least adequate. It might be a classic and feel a bit outdated and weak on the solution side, but to understand the problem properly is the first step to appreciate possible answers. And Alan Cooper didn’t stop there. Read his ongoing series “About Face” (current version: 4.0) for lots of solution ideas.

Epilogue

And that’s it. These are the ten books I recommend everybody who wants to read good books about software development. And just a few days ago, another student asked me if I’m seriously recommending twenty years old books about topics that change fundamentally every five years. I am serious. If you read just one book of this list and judge afterwards, you’ll see what I mean when I say that there are timeless topics even in an ever-changing field like software development. Maybe you want to begin with “Refactoring” and compare it to the second edition (Java vs. JavaScript). The underlying concepts stay the same, no matter the syntax.
I hope you enjoyed this list. And I hope the student who originally asked the question got his answer. Are there books you want to recommend? Drop a comment below or blog about them! The average software developer reads less than one book per year. Maybe our insistence can change that a bit.

Ten books that shaped me as a software developer – Part I (Books 0 to 4)

I was asked what books shaped me as a software developer the most. Here is my answer, or the first part of it.

Last week, I’ve done a question and answers event with students when the question came up what the most influential books were that I have read as a software developer. I couldn’t answer the question right away but promised to compile the list with short descriptions of the book’s influence. And here it is – my list of books that left a big mark in my day-to-day work. Others have done the list of books thing before me, and most lists contain the same books over and over again. I take it as an indicator that my list isn’t too far off.

Prologue

Before I start the list, I want to say a few things. The list isn’t ordered or ranked. I describe the effects of each book from my current standpoint, sometimes 20 years after the fact. I read a lot more good, interesting and inspiring books in the last 20 years and they all added to my work personality. But with all the books on my list, I felt enlightened and vibrant with new ideas. They didn’t just inspire me, they elevated my thinking. And because of this criteria of immediate improvement, one book is missing from the list. It’s the first “serious” software development book I’ve ever read in 1998: “Design Patterns“. The book was just too much for me (and my study group peers) to handle such early in our careers. We were in our first year of study and had a lot of other battles to fight. I crossed it from my reading list and moved on. Years later, I re-read it and saw so much insight I plainly missed the first time, but gathered elsewhere since. If you want to read this classic, don’t hesitate! If you “only” want to know about design patterns, there’s a better book for that: “Head First Design Patterns“.

The Pragmatic Programmer

https://images-na.ssl-images-amazon.com/images/I/41BKx1AxQWL._SX396_BO1,204,203,200_.jpgMore by chance, my co-founder stumbled upon “The Pragmatic Programmer” in 1999 and devoured it. Then he gave the book to me and it shattered me to my core. I thought I was a decent software developer and here are Dave Thomas and Andy Hunt and talk about things I didn’t even knew existed. A healthy dose of Dunning-Kruger effect is crucial in everybody’s upbringing, but this book ended my overestimation once and for all and gave my studies a focus and direction I wouldn’t have thought to be possible before. I own my whole career to this book, at least in terms of work ethics. I cannot fathom how my professional life would have played out otherwise.

Refactoring

https://images-na.ssl-images-amazon.com/images/I/51K-M5hR8qL._SX392_BO1,204,203,200_.jpg

Also in 1999, Martin Fowler wrote his instant classic “Refactoring“. We bought this book at the first chance we got and raced through the pages. I was a Java developer back then and with most of the examples being in Java, the book needed no explanation nor translation. It was directly applicable knowledge that gave me years of experience virtually for free. This book is a must-read even 20 years later, and has just recently had the second edition announced, this time with code examples in JavaScript. I thought it was a joke first, but I guess it makes sense.

Working Effectively With Legacy Code

https://images-na.ssl-images-amazon.com/images/I/51EgCCLOWxL._SX376_BO1,204,203,200_.jpgIn 2004, Michael Feathers wrote a book that contains his 20+ years of experience with software development and named it “Working Effectively With Legacy Code“. Well, joke’s on you – I don’t write legacy code, my code is perfect. That wasn’t my attitude since 1999 (see list entry #1) and I took this book everywhere. It’s a heavy one, but I read it in the tram, right before the movie starts in cinema, during breakfast, lunch and dinner and virtually any other circumstance. I realized that reading this book will gain me experience a lot faster than actually writing code, so I just stopped for a few weeks. This book answered a lot of mysteries in the form of “is there really no better way to do this?” for me. And it introduced the concept of code seams for me that permeates my work ever since. I can clearly remember the day when I looked at my existing code again and saw the seams for the first time. It was truly eye-opening for me.

Analysis Patterns

https://images-na.ssl-images-amazon.com/images/I/41uNHkTq8NL._SX378_BO1,204,203,200_.jpgMartin Fowler was a very productive author in the late nineties. I’ve read most of his books from this period, if maybe with a few years delay. “Analysis Patterns” from 1996 arrived in my bookshelf in the early 2000’s and was my wake-up call to seeing models instead of actualities. I’ve given this book to many peers, but haven’t received the reactions that I had with this book: Being taught a language (with a graphical notation) that can express actual problems in terms of an overarching solution. Since then, I’ve seen the same solutions applied in many different forms, with many different names and a lot of different special requirements. But they all derive from the same model. This effect was promised by the “Design Patterns” book, but for me, delivered by “Analysis Patterns”. Even Martin Fowler admits that the book is showing its age, but for me, its timeless.

Peopleware

https://images-na.ssl-images-amazon.com/images/I/51MlUgcSICL._SX331_BO1,204,203,200_.jpgSince the late 80’s, Tom DeMarco and Timothy Lister wrote one book after the other. Each book describes a common business-oriented problem and at least one working solution for it. And yet, the very same problems still persist in the business world. It’s as if nobody reads books. “Peopleware” was written in 1987, 30 years ago, and discovered by me and my peers in the late 1990’s. We talked about this book a lot, as it described a (business) world where we didn’t want to work in. We wanted to do better. In a way, this book was a spark to found our own company and don’t repeat the mistakes that seemed to be prevalent in our industry. If you’ve ever shaken your head about “the management”, do yourself a favor and read this book. It will pinpoint the precise problem you’ve felt and give you the words to describe it. And if you’ve read “Peopleware”, liked it and want more, there is good news: There is a whole series waiting for you (not just Vienna).

Epilogue to Part I

These are the first five books from my list, with the last entry being more of a catch-all for a whole series. Remember that this isn’t a generic “go and read these books if you want to call yourself a professional software developer” list. I’m not gatekeeping and it would be useless to even try to do so. These books helped me further my career in the last 20 years, they won’t necessarily help you for the next 20 years. Good books are published every year, you just have to read them.

I’m looking forward to share the second part of my list in the next blog post of this series. Stay tuned!

Book review: Clean Architecture by Robert C. Martin

A personal review of the book “Clean Architecture” by Robert C. Martin. Spoiler: you might want to read it.

In 2008, a book changed the way software developers around the globe talked (and hopefully) acted about their code. Robert C. Martin’s “Clean Code” was and still is a cornerstone of modern software development. The book itself is remarkably weak in its code examples, but has strong and effective messages on the level of practices and principles. Even today, ten years later, this is the one book that most of my students read and are passionate about. It’s a book that speaks reason to them, albeit with some contortion because of high volume. Robert C. Martin has the tendency to preach 200 percent in order to still get the half-convinced to an acceptable level.

So when a new book from him, called “Clean Architecture”, appeared on the horizon, I was thrilled. Would it be groundbreaking like “Clean Code” or a dud like “The Clean Coder” (sorry, my opinion – this is a personal review, not an academic evaluation)? I’ve read some very good books about software development (like “The Pragmatic Programmer”), fantastic books about programming (“Refactoring” and “Working Effectively With Legacy Code” come to mind) and even some mind-blowing pieces about design and emerging architecture (my first read of “Growing Object-Oriented Software, Guided by Tests” felt like a personal audience with Steve Freeman and Nat Pryce). But all these books dealt with tactics, with the immediacies of software development. Don’t get me wrong! This is the most important part and it helped me tremendously. But there are parts “above” the footwork that needs to be addressed in bigger systems, too.

And there, the literature got thin or stale. Books about software architecture talked about large-scale architectures (so-called “enterprise scale” systems that span from horizon to horizon, like in “Patterns of Enterprise Application Architecture”) or had the taste of dry plywood because it was clear that the findings were from another era and would translate badly into modern software development.

“Clean Architecture” begins with a quick and focused overview over the current programming paradigms and a conclusion that there are no different “eras”. We didn’t get better in designing systems, we just changed the aroma and color of our failures. Future generations will look at our code and architectures as scornful as we looked at the ruins of the systems of our ancestors. And make no mistake – the ruins are still in production today! We cannot place our hope on another new and liberating programming paradigm because there probably won’t be one. We have to make do with what we have.

This is the first six chapters of “Clean Archicture”. The chapters are short and on point and I loved every line of it. It probably isn’t the most comprehensive and balanced description of structured, object-oriented and functional programming, but it provides a narrative that is intuitive and convincing – your mileage may vary, I was hooked.

In the next five chapters, Robert C. Martin reiterates the known SOLID design principles. I rolled my eyes when I glanced the content because I’ve read it like a hundred times in maybe as many books. But I decided to read it once more and I’m glad I did. The principles are known, but the underlying revelation is woven into the text like a good thriller. I hesitate to give away too much, because I really think this book can be spoiled – just like a good thriller. I was sold. Robert C. Martin can explain the same old SOLID to me and I still learn something and have fun.

Then, the part about components. It feels like an intermezzo to an even better thriller, because suddenly there is math and formulas. Its interesting and noteworthy, but if you followed the metrics discussion in the last fifteen years, the excitement of this part will be dampened.

But wait, there is more! Starting with page 133 of 321 (yeah, the Appendix is interesting, but more in the “The Clean Coder” way of things), there is the central question: “What is Architecture?”. There it was again, the thrill that in every line, there could be insights that are worth weeks of thoughts. I read this part in the train from south to north germany and I stared out of the window often, following my own train of thoughts.

Again, no spoilers, but the way the answers are given is so refreshing and the answer itself is so simple that I’m surprised that it took me this long to not come to the same conclusion. Software architecture lost some of its mysticism, but gained a lot of applicability for me. I was spent (in a good way).

And then, on page 200, finally, “The Clean Archicture”. Well, I watched all the trailers on this topic, so my surprise wasn’t really there, but with all the knowledge and insights from the first 200 pages, I could have “invented” the Clean Architecture by myself then and there. It’s more or less the logical next step from the prerequisites. I applaud this masterwork of storytelling, because it doesn’t overwhelm the reader with the genius of the narrator, it drives him to connect the dots himself.

The rest of the book, like the title of part VI, are just “Details”. The central message  – The Dependency Rule, this little spoiler should be allowed – is simple, convincing and deduced from the beginning. I’ve seen the heart of software architecture and it is beautiful.

I even forgive the many typos and grammatical errors (far more than usual) and the bulky appendix for this ride. This book is definitely up there with “Clean Code”. It is accessible, has a clear message and profound effects. And it refrains from preaching most of the time. No need to turn it up to 200 percent when your message is so convincing in itself.

Conclusion: If you are interested in software development with a structure, go grab this book as soon as possible. We’ve waited long enough!

Quick and dirty is a skill

This post is a reminder, first and foremost to myself, that it is important to work according to what’s essential right now: quality or speed.

Being clean coders we build our software based on quality and reflect on how we do it. We set internal standards in code and UIs, we write tests, we polish.
But there are times when all this focus on quality is obstructive. Times when we need to learn something. For example: at a start of a project when fundamental questions like is it feasible, how should this interaction work, what’s the right order of steps are unanswered, learning needs to be as cheap as possible.
Here quick and dirty is important. The problem is our ego. We want to polish it, we want to build real software with a sound structure. But quality takes time. The problem is quality is not important when answering the fundamental project questions, learning is. May be a mockup in Powerpoint is enough? (not even writing code? ugh). A simple sketch on a piece of paper. Or maybe just a quick demo hacked together in an afternoon.
I know these suggestions may insult our pride. But we need to focus on what’s important: sometimes that’s quality, sometimes that’s speed.
Decades ago when I started coding, quick and dirty wasn’t a problem. Everything I wrote was quick and dirty. I was learning all the time. Over time I got better at developing software, structuring applications and building robust systems. But quick and dirty was lost along the way.
When you write something for the purpose of learning it can happen that you are wrong and all the code has to be thrown away. If it was just 2 hours patching something together that’s okay, but what if you spent a whole week? Just like writing quality software, quick and dirty is a skill in itself and as with other skills we need to practice it.
But beware this is not only a problem at the start of a project: often as developers we tend to overthink something, we plan for every possible outcome, imagine scenarios with weirdly acting users or systems. This is the time to stop and implement something to learn. To get feedback. Not to overanalyse or overdesign. Just release something and test it with real users, it doesn’t need to be part of the software in production, just use a demo or a staging environment. But if you need to learn something, focus on that, not on quality.

How do I start a project

On my quest to build better software for people and their needs I try to move my current agile project approach to a more user centered and outcome oriented one.

This starts right at the beginning of a project. After getting the go from the client I start with meeting the project leads on the client side, the ones who will make decisions and control the way of the project.
I like to take an assumption driven process or learning focussed one to ask questions and clear my assumptions on my way.
The first questions I have are:

  • who will use the software
  • who will be affected by the software/project
  • what are their goals/expected outcomes, what if they could choose only one
  • what do they expect from the software
  • what will happen if the project stalls or even fails

The people using the software aka the users are one of the main focus during the project but also the people who get benefits from the software without directly using it are really important and should not be neglected. These can be the people responsible for operating the software or managers getting reports from actual users. I keep them in mind so that other parts which are often missed during a user centered approach are considered.
All these people have some expectations how the software will affect them, some even have goals or need something to come out of the project. These outcomes cover a great range: from measureable business goals like increasing revenue or retention rate, to personal benefits like visibility. It is important to get a rough priority, I use a narrowing question like ‘what if you could choose only one’.
Besides from goals and outcomes people have also imaginations how the software will be used by them, in which context and how often.
These are the positive effects of the project and the software but all is not sunshine, so I also look at what will happen if the project is delayed, stops or even *shudder* fails. These are the risks that I need to consider and may be even plan for.
All these questions help me frame the project from the end. I know what goals to aim for and in which direction the journey goes.
This is my first step to build a shared understanding among the project participants. The steps to learn about what picture they have in mind. My questions and their answers help me to clarify the direction. After that I need to plan the first phase. For this I have to clear my mind and start with a beginner’s mind to find my hidden assumptions. Every assumption I or other have need to be called out explicitly. I have to capture it and formulate a corresponding learning step.

But this is a topic for another post…

The definition of done

From large to small, from projects to issues, a team needs to define when they are considered done.

From large to small, from projects to issues, a team needs to define when they are considered done.
This decision differs from team to team, some have steps to done, others just one state. Even the words used in your issue tracker reflect your choices: what does ‘fixed’ mean, what is ‘closed’ used for…
Even some practices like test driven development define a state of done: the code is done if all tests are green and it is refactored.

What’s your definition of done?

Let’s take a look at some examples:

  • tests are green and code is refactored
  • QA says ok
  • customer/stakeholder/product owner accepts the issue
  • developer thinks the code reflects the description in the issue
  • a predefined spec, maybe even with an acceptance test, is fulfilled
  • no bugs were found while clicking through
  • the code is merged with the master branch
  • the continuous integration tool has found no errors

The problem with this ‘definition of done’s is that either they look for an external person to accept by their opinion/guideline or concentrate on some output. But the people needing the software do not want the software in its own regard. They want to reach a goal through the software. The software is a mean to an end: their goals. Without defining the goals and needs beforehand you are either doomed to guess them and are at the mercy of arbitariness (from your point of view) or concentrate on some measurable output like code, tests or a completed feature.

Defining what the user wants to do with this new feature or project should be the first thing in a project right after the initial introductions. Who will use the app or the feature? (the intended audience, the users) What do they expect from it? (the benefits) What goal do they want to reach?
With this questions and answers you have a target. After completing the issues or project you can see if the target has been reached, if the goals are met. It might be the same with an acceptance process from a stakeholder but here you know the target beforehand not after.