I've seen it plenty, what I don't ever recall seeing is a book or article that says "this is how you should do it in production". Generally there is just some h

I've seen it plenty, what I don't ever recall seeing is a book or article that says "this is how you should do it in production". Generally there is just some hand waving over important other stuff like error handling you should take care of in a real system. I've also seen lots of production code that doesn't look that different from the code examples you shouldn't use in production. From my experience of real production codebases, the difference is mostly in accumulated bug fixes, which may or may not be documented but often make the code less clear and in lots of logging and debug code in parts of the code base that are particularly bug prone. If I was a cynic, I'd be tempted to conclude that we don't actually know as an industry how to write "production code", all we know how to do is write non production code and then try to patch it up until it kind of works in production.