Monitoring changes in the dom tree

Thank you for taking a look at the question.

I'm thinking of making a Google SERP scraper. It's simple enough to get the title and URLs, but we need to have a mechanism to detect when the dom tree changes, as it needs to be modified.

I've looked at things like MutationObserver (javascript), and I believe these detect changes to the page you have open. I would like to build a system that can detect changes to the layout of a web page. I think it's a batch check at regular intervals. Is that process something that gets the elements and uses regular expressions and so on to determine them?

Does anyone have any ideas?

Best regards.