I love to be a windows repairer

Posted in: self, programming.

This is something I was thinking about yesterday night, trying to get asleep. Some of my colleagues are very argumentative about the role a computer scientist must have: someone thinks that only who builds abstractions (call him architect or whatever) is the only person worth respect in a company. Others, like me, thinks that any programming role could be something extremely interesting and compelling if you see it on a different perspective.

The windows repairer

I don’t know if someone come up with this definition, but I could easily define myself a “windows repairer” or a “windows fixer”, if you prefer. The “broken window” paradigm was popularized by Andy Hunt and Dave Thomas in their masterpiece The pragmatic programmer. In one of the first tip of the book they introduce the broken window principle: sometimes, all you need to make your software rot is a broken window, intended as a single messy point where you introduce an hack, code duplication or a not-optimal design choice. The “broken window” is dangerous because it rapidly becomes a code quality metric. You start saying “Yea, after all I already used that hack there, so I’m gonna use it too..”, and pretty soon you got a building with two broken windows, and the overall code quality degrades. Conversely, if you have a clean code, you are more reticent about introducing and hack or a poor programming choice. You feel the quality and you are proud of the “perfect temple” you have created.

The real world

Most of the time, though, you can’t program that way. The real world is full of broken windows. Reasons are multiple: short deadlines, throw away code, inaccuracy and so on so forth. You sometimes are put on a legacy project and they say to you “We have this huge amount of spaghetti code, and we want brand new features on top of that”. Here programmers are split in a half: One half just hate to maintain and improve legacy code, other half just love it. I don’t know if I really “love” to maintain spaghetti code, but I think that sometime fix is better than create.

The false misconception

There is this false misconception that brings programmer to prefer evergreen project. Sure, you must be creative to design a new architecture, but I think that the same level of creativity can be achieved modifying legacy code. How? Let’s take as motto what uncle Bob says in his authoritative book Clean Code: he says that we should always leave the camp cleaner than when we have found that. What does it mean? That we should put all our effort in improving the quality of the code we write and maintain.

Work as a surgeon

A surgeon operates on a patient, sometimes working and reversing a very bad situation. He cures the patient, not just throw away his work. He cares in what he does, because he knows that a human life is at stake. As a surgeon, we must care about our craft, even if craft is something we have inherited. We can start developing adequate code coverage to be confident we won’t break anything already coded, and then we can start operating. We can begin simplifying messy functions, extracting other functions/methods and testing everything as we proceed. It can become fun and addictive: how we can further simplify this code? What lovely one-liner can we use? If we love functional programming, we can replace our messy for with map or using filter elegantly to restrict our result. If we operate in the Java World, for example, we can use the Guava libraries to prevent us from the dreadful NullPointerException. Conversely, if we just think “this code sucks, I’m not gonna to maintain it, I’m gonna write my layer on top of that” sooner or later you we’ll be caught up into the “broken window paranoia”. Since the code quality is low and most of your design choices were biased by that crappy code, you’ll start to see your code with the same nasty glance you look at the legacy code. You don’t feel this system like your craft, so you are not too motivated in make that beautiful. Conversely, if you spent a certain amount of time improving the existing code base, not only you’ll end up with a more robust system (which is always an advantage) but you’ll begin feeling proud of what you have done: “Look at this code”, you’ll say - “it was crap three months ago and now is fully of best practices!”. You will begin considering that code a your craft, and you’ll be more cautious when you’ll modify it. You will be more motivated in keeping as clean and as beautiful as you can.


Sometimes work with existing code sucks, but you have to put up with it. You have two ways to approach the problem: the “wrong” way, when you want to hide the legacy code and the “right” (at least for me) way to do that. Embrace the existing code, turn something ugly into something beautiful. Be a savvy artisan and like a sculptor painstakingly improve your creation.

In other terms, fix your windows.

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