How does Yandex Webvisor work?

Question

Web development

Hello! Please explain how Yandex Webvisor works from a technical point of view.
On the Internet, I did not find anything sensible. They write that if you change the content on the site, then the entries made earlier will not be relevant. I added an entry to the site and even changed the design of the site completely, but the old design remained on the posts without a new entry. Those. it does not load the current version of the site into the Webvisor window.
I know it's possible to track mouse coordinates with JavaScript, but I still can't figure out how it works.
So I went to the site and stayed there for a minute. Metrica counter gave me some unique number. And during the whole minute, the script installed on the site recorded the coordinates of the mouse position somewhere?
And then, when I start the "record" of this user in the Webvisor, does the view window display the current site embedded in the window through the iframe tag, and then the mouse cursor moves in this window, to which the coordinates that were recorded earlier are transmitted? But how does the cursor move in the viewport if I have my own cursor? But since I wrote above that even after changing the entire design in early posts, the design remained old, it turns out that it does not substitute the current version of the site through the iframe.
I'm completely confused myself. Please explain how this all works. It's all done in JavaScript, right?

Answer 1

You have a lot of questions that you answered yourself.
Some work in JavaScript, some in a server-side language, since JS sends data about the behavior of the client to the server via WinSocket or Ajax. There they are stored. There is a setting in the webvisor that allows the DOM tree of the current state of the page to be saved on the server, that is, the visitor takes HTML and sends it to the server via JS, and it is already saved on the server. There is another option when the robot comes and takes the HTML of the current state of the page, that is, then it is not transmitted from the user via JS, but there may be a difference in the information on the page, since the user could be authorized, and the Yandex robot will not be authorized if it arrives. Here I described why the iframe displays the version of the page that was when you visited (but I repeat, it seems like there is some kind of setting, you can disable this moment and the new version will be displayed).
Regarding the cursor, JS does not trade your cursor, but uses drawing to show how the cursor moved in time. And you can draw at least a circle, at least a square, at least a pointer similar to the cursor - so the answer is for you, the web browser does not touch your cursor when playing.
I think that in vain you marked the question as difficult. If you roughly answer how it works or assume how it is quite clear in my opinion. I'm not talking about taking and making an analog. In any case, this would already be a task not for the site of questions.
Let me know in the comments if there is anything else you need to clarify.