The fourfold path to software quality

How do you achieve software quality? How do you write software that actually works, software that isn’t buggy, software that doesn’t result in 4AM wake up calls when things break in production?

There are four different approaches you can take, four paths to the ultimate goal. Which path you choose to take will depend on your personality, skills and the circumstances of your work.

The path of the Yolo Programmer

The first path is that of the Yolo Programmer. As a follower of the famous slogan “You Only Live Once”, the Yolo Programmer chooses not to think about software quality. Instead the Yolo Programmer enjoys the pure act of creation; writing code is a joy that would only be diminished by thoughts of maintenance or bugs.

It’s easy to look down on the Yolo Programmer, to deride their approach a foolish attitude only suitable for children. As adults we suppress our playfulness because we worry about the future. But even though the future is important, the joy of creation is still a fundamental part of being human.

When you have the opportunity, when you’re creating a prototype or some other code that doesn’t need to be maintained, embrace the path of the Yolo Programmer. There’s no shame in pure enjoyment.

The path of the Rational Optimizer

In contrast to the Yolo Programmer, the Rational Optimizer is well aware of the costs of bugs and mistakes. Software quality is best approached by counter-balancing two measurable costs: the cost of bugs to users and the business vs. the cost of finding and fixing the bugs.

Since bugs are more expensive the later you catch them, the Rational Optimizer invests in catching bugs as early as possible. And since human effort is expensive, the Rational Optimizer loves tools: software can be written once and used many times. Tools to find bugs are thus an eminently rational way to increase software quality.

David R. MacIver’s post The Economics of Software Correctness is a great summary of this approach. And he’s built some really wonderful tools: your company should hire him if you need to improve your software’s quality.

The path of Mastery

The path of Mastery takes a different attitude, which you can see in the title Kate Thompson’s book Zero Bugs and Program Faster (note that she sent me a free copy, so I may be biased).

Mastery is an attitude, a set of assumptions about how one should write code. It assumes that the code we create can be understood with enough effort. Or, if the code is not understandable, it can and should be simplified until we can understand it.

The path of Mastery is a fundamentally optimistic point of view: we can, if we choose, master our creations. If we can understand our code we can write quality code. We can do so by proving to ourselves that we’ve covered all the cases, and by learning to structure our code the right way. With the right knowledge, the right skills and the right attitude we can write code with very few bugs, perhaps even zero bugs.

To learn more about this path you should read Thompson’s book; it’s idiosyncratic, very personal, and full of useful advice. You’ll become a better programmer by internalizing her lessons and attitude.

The path of the Software Clown

The final path is the path of the Software Clown. If Mastery is a 1980s movie training montage, the Software Clown is a tragicomedy: all software is broken, failure is inevitable, and nothing ever works right. There is always another banana peel to slip on, and that would be sad if it weren’t so funny.

Since the Software Clown is always finding bugs, the Software Clown makes sure they get fixed, even when they’re in someone else’s software. Since software is always broken, the Software Clown plans for brokenness. For example, if bugs are inevitable then you should make sure users have an easy time reporting them.

Since banana peels are everywhere, the Software Clown learns how to avoid them. You can’t avoid everything, and you won’t avoid everything, but you can try to avoid as many as possible.

If you’d like to avoid the many mistakes I’ve made as a software engineer, sign up for my Software Clown newsletter. You’ll get the story of one of my mistakes in your inbox every week and how you can avoid making it.

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These are the four paths you can take, but remember: there is no one true answer, no one true path. Try to learn them all, and the skills and attitudes that go along with them; you’ll become a better programmer and perhaps even a better person.