I implemented a feature on a site that in short is the following:
There should be a pop-up dialog after page is visited more than 3 times. The pop-up is a simple dialog with one button which is actually anchor(link). All the content(HTML Javascrpt, CSS) is visible from the browser dev-view, it is server site rendered. There is only one specific: The popup is shown if an AJAX request receive '{status: "show"}'(json) response, then via CSS(display) the dialog is shown to the user. I was asked if this implementation is SEO(bots, crawlers) friendly.
I have been reading in the internet how these spiders/crawlers work - and generally what I learned is that they find links/anchor-tags in the HTML and follow them, thus traversing the linking tree. So there might be a problem with AJAX requests. Though I read that google spiders can follow ajax links and trigger ajax requests as well.
Unfortunately I couldn't figure it out - Do this type of implementation disrupt the SEO of the site or not? I mean all the links are still there on the site page - visible for the bot. Only JSON data is fetched via AJAX call - and only CSS is changed to show/hide the element.