I have never in my career seen a (useful) program without bugs. I'd go so far as to say that, at least for most software, the optimal amount of bugs is not zero - if you write your code carefully enough to never have bugs, you will ship far too slowly. The point of code is not to be beautiful and perfect and well designed - it is to solve problems in the real world.
By the way, all hardware has bugs too; we just don't see them often because the programmers building the stacks that we run our code on work around them.
By the way, all hardware has bugs too; we just don't see them often because the programmers building the stacks that we run our code on work around them.