[Double_a_92]

We don't. Everything that is not part of the code will just get out of date.

It's just best to reduce external documentation, or at least bundle all in one place.

What works best is just creating a rough sketch of the idea, and store it somewhere next to the code with a datestamp. So it's clear that it's out of date, but if you really need some hint of how it was intended to work you can still look at it. (That is usually some class diagram, or a word document with explanations...)

Or it's just kept up to date by being used. E.g. we have step-by-step instructions for certain tasks, that devs occasionally need to follow. So if things get annoyingly out of date we just fix the instruction that has become unclear with time.

[ardalanpouya]

I like the idea of timestamping docs. How often do you run into something being "annoyingly out of date"? Asking because it happens alot for us with onboarding docs specially. I am trying to find out what we are doing wrong