Here is my list of heuristics and rules of thumb for software development that I have found useful over the years:
1. Start small, then extend. Whether creating a new system, or adding a feature to an existing system, I always start by making a very simple version with almost none of the required functionality. Then I extend the solution step by step, until it does what it is supposed to. I have never been able to plan everything out in detail from the beginning. Instead, I learn as I go along, and this newly discovered information gets used in the solution.
I like this quote from John Gall: “A complex system that works is invariably found to have evolved from a simple system that worked.”
Here is the story of a bug that I caused, found, and fixed recently. It is not particularly hard or tricky, and it didn’t take long to find and fix. Nevertheless, it did teach me some good lessons. Continue reading
To trouble-shoot software, logging of some kind is essential. But for most systems, it is simply not possible to log everything that happens. Many systems and logging frameworks let you limit the amount of data by giving a logging level (e.g. error, warning, info, debug) and by specifying where in the code logging should be done. An alternative way of limiting the data is to use session-based logging. You then get all data pertaining to a specific session, but nothing for any of the other sessions. Continue reading
One common reaction to my post on writing debuggable code was: you don’t need logging, just use a debugger. While there are cases where a debugger is the best option, there are many reasons why having proper logging in place is superior to using a debugger for trouble shooting. Continue reading
When there is a problem with your software, the first thing you usually ask for is a log showing what happened (provided you write debuggable code), and the version of the software that was running. But it is easy to have the revision of the software automatically added to the log. Continue reading
All programs need some form of logging built in to them, so we can observe what it is doing. This is especially important when things go wrong. One of the differences between a great programmer and a bad programmer is that a great programmer adds logging and tools that make it easy to debug the program when things fail.
When the program works as expected, there is often no difference in the quality of the logging. However, as soon as the program fails, or you get the wrong result, you can almost immediately tell the good programmers from the bad. Continue reading
Every once in a while I read something along the lines of: “most developers just want to write new features, they don’t want to work with maintenance and bug-fixing”. If that’s true, then most developers are missing out on the fun and benefits of finding and fixing bugs. Continue reading