How do search engines view ajax script loading?

Question

Search Engine Optimization

The question is, how do search engines view ajax script loading?
That is, the page seems to be loaded, but after a second, scripts start to work and load some information, for example, information about the weather or currency, etc. , such requests can take another 1-2 seconds, and this is how the search engine looks at it, does it take what was immediately given to it and notes that the page loads quickly, or does it wait until everything is done and then notes?
It’s just that I’ve already read in many articles that the page load speed affects the site’s rating, while I also need to show the user the information he needs, for example, the weather in his region, while you need to request data, etc.

Answer 1

• Sites using AJAX for Google
  
• Indexing AJAX sites in Yandex
  

Answer 2

Google declares something like 5 sec.
Yandex simply skips the Java script.
Alternatively, use the page prerender in a headless browser and upload everything to the server.
Or think about rendering on a static server and add interactive from above.
By interactive I mean shopping cart, featured products, different polls, flash blocks

Answer 3

Use Lazy Loading: Understanding .

Answer 4

If it's possible not to use AJAX, then don't.
If there is no way without Ajax, then follow the recommendations of search engines (in fact - generate a separate version of the page for search engines)