# Things You Should Never Do, Part I  ## About - Author: Joel Spolsky - Title: Things You Should Never Do, Part I - Tags: #articles - URL: https://www.joelonsoftware.com/2000/04/06/things-you-should-never-do-part-i/ ## Highlights We’re programmers. Programmers are, in their hearts, architects, and the first thing they want to do when they get to a site is to bulldoze the place flat and build something grand. We’re not excited by incremental renovation: tinkering, improving, planting flower beds. There’s a subtle reason that programmers always want to throw away the code and start over. The reason is that they think the old code is a mess. And here is the interesting observation: *they are probably wrong.* The reason that they think the old code is a mess is because of a cardinal, fundamental law of programming: It’s harder to read code than to write it. - Note: And it's harder to understand code than to read it. --- The idea that new code is better than old is patently absurd. Old code has been *used*. It has been *tested*. *Lots* of bugs have been found, and they’ve been *fixed*. There’s nothing wrong with it. It doesn’t acquire bugs just by sitting around on your hard drive. Au contraire, baby! Is software supposed to be like an old Dodge Dart, that rusts just sitting in the garage? Is software like a teddy bear that’s kind of gross if it’s not made out of *all new material*? - Note: This is a fascinating idea - the longevity of software. What breaks it is its environment; many programs will no longer run for software or hardware reasons, --- It’s important to remember that when you start from scratch there is **absolutely no reason** to believe that you are going to do a better job than you did the first time. First of all, you probably don’t even have the same programming team that worked on version one, so you don’t actually have “more experience”. You’re just going to make most of the old mistakes again, and introduce some new problems that weren’t in the original version. - Note: What a fascinating idea! Sometimes it is the current team that has the magic - worth more than the sum of their parts. ---