Can Google catch you for doing this?

When it comes to paying for guest posts or link insertion to the existing articles, can Google actually find out about it and punish your website for this? As we all know that buying links is against their policy.

If yes, then what are the precautions that one should follow not to get caught (other than avoid paying for links) ?

P.S. I am NOT talking about buying backlink services or PBN links. I am talking only about paying to stand-alone legit websites that charge a fee for link insertion/gues post publishing.

I think as long as it looks like it was the webmaster who made the change, in your case posting a link to an existing article, it's fine. Google doesn't penalize your site for updating your existing artciles. Infact major news sources update their pages all the time.

That is called niche edits and there are lots of seller over here doing that.

So you can do it.

Any kind of link placement is generally against the search engines' TOS. Just like Guest Posts, Niche Edits technically violate the TOS but they are still safe and widely used.