Friday, 15 October 2010

This code is crap

Helping customers get the most out of their systems is good and interesting job. One gets to know a lot of industry sectors, processes and ways of working, as well as some good people.

Invariably, the job involves reading code. And writing code, usually a tiny fraction of the whole body, because you focus on the parts that provide most benefit to your customer. Whenever I wrote code, I always try to make it stand out for its clarity, performance and readability. Experience has taught me that having your code reused or called from a lot of places is a sign of a happy customer, so it made sense to do my best for the customer.

As you can imagine, one develops a good sight for reading code. And I've seen my fair share of bad code over the years. Very very bad code. It is difficult sometimes to keep yourself neutral and resist the temptation to think of yourself as some kind of elite coder that can see what other people can't. With enough time and experience you learn that there are a number of factors, all of them human related, that can affect significantly the outcome of your work. Even if you try to deliver your best effort, sometimes you just were under pressure to meet a deadline and had to rush something out. Or perhaps you have a child with a cold waiting for you at home and that worries you much more than the quality or performance of what you're writing.

But that perception changed when I recently had to look at some code written five years ago.

At first, it was not that bad: at least the formatting was consistent. But it was pretentious and sophisticated beyond necessity. There were missing oportunities for simplification everywhere. Performance could be easily doubled with a number of simple, apparently obvious changes. There were comments, but essentially useless because they were centered in irrelevant parts of the code. Design decisions were not explained properly, there was no summary explaining why on earth certain algorithm was chosen or modified.

There were obvious refactoring spots all over the place. The code could have been much sorter, cleaner and efficient.

I was becoming impatient with that code, and finding progressively more difficult to sympathize with the original coder.

The only problem was, I was the one that wrote that horrible code.

As it turns out, that was I considered good code five years ago. I was so shocked that I started to dig around other, older fragments, of my old code. Ten years ago it was even worse. What I wrote fifteen years ago was practically unreadable.

Suddenly, I felt the urge to fix all that. I then realized that these lines are still happily executing many times every day, processing millions of transactions. And nobody yet has replaced it with something better, probably because they don't need to touch it.

It took me a while to recover from, but then I think I learned something. I’m not as a good coder as I think I am. You’re probably not a good coder too. Yes, there are good coders out there. Probably the club of good coders has members whose last names are Knuth, Kernighan, Aho, Torvalds, Duff or Catmull. But I'm not there. Not now at least.

I'm now a good enough coder to recognize good code. Perhaps over time I'll get better, enough to be considered a good coder. In the meantime, what I deliver seems to be good enough.

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