What’s your process for keeping internal docs from going stale?

I've been working on internal documentation recently, and one thing that keeps coming up is that creating the documentation isn't necessarily the difficult part keeping it accurate is.

A process gets documented, someone changes a few steps a month later, and eventually the original guide no longer matches what people actually do.

I've seen teams handle this in very different ways:

• Assign an owner to each document

• Review SOPs every few months

• Update documentation whenever a process changes

• Keep a video walkthrough alongside the written instructions

• Just fix the documentation when someone notices it's wrong

The last one seems to happen more often than people admit.

I'm curious what this looks like on other teams, especially when there are dozens or hundreds of internal processes.

How do you actually know that a piece of documentation needs to be updated?

And who is responsible for making sure it happens?

I'm more interested in what people are actually doing day to day than what the ideal documentation process looks like on paper.