How does software get reliable at all, ever? In my experience there are two ways:
1. You write reliable software from the start. It feels a lot like writing a mathematical proof, or at least sketching one. After a few dumb bugs are fixed the code continues to work without issue, year after year, and nobody ever looks at it again. (This isn't as hard as it sounds! It's not the right approach for everything, but it should be more widely used than it is.)
2. You write normal software, i.e. unreliable crap, but you look at the ways that it goes wrong and fix them. This requires that you put some work into detecting that things have gone wrong. A lot of software companies will trace all crashes, and aggregate stack traces and logs from them. In this kind of environment, you can improve software reliability by sticking a paranoid number of assertions in your code and obsessively checking to see what triggered them. After a while all the common problems will have been removed, and the remaining bugs will be less prevalent than hardware failures -- and then you can declare victory.
1. You write reliable software from the start. It feels a lot like writing a mathematical proof, or at least sketching one. After a few dumb bugs are fixed the code continues to work without issue, year after year, and nobody ever looks at it again. (This isn't as hard as it sounds! It's not the right approach for everything, but it should be more widely used than it is.)
2. You write normal software, i.e. unreliable crap, but you look at the ways that it goes wrong and fix them. This requires that you put some work into detecting that things have gone wrong. A lot of software companies will trace all crashes, and aggregate stack traces and logs from them. In this kind of environment, you can improve software reliability by sticking a paranoid number of assertions in your code and obsessively checking to see what triggered them. After a while all the common problems will have been removed, and the remaining bugs will be less prevalent than hardware failures -- and then you can declare victory.