How do I improve the site's ranking in the search?

To make your site pages take the desired position in the search results more often and bring more visitors, track the following site indicators:
Quality
Check out signs of a low-quality site from the Yandex point of view, and also make sure that the site doesn't have violations (on the Diagnostics → Security and violations page in Yandex.Webmaster).
Security
Check that the site is safe for visitors on the Diagnostics → Security and violations page. If Yandex.Webmaster detected a threat, follow the service's instructions and see the What should I do if a site security threat is found? section.
Convenience

Use the recommendations for creating a site. To display the site on mobile devices, create a mobile site version or use Turbo pages.

Specify the site region in Yandex.Webmaster on the Site information → Region page. For details, see the Region section.

Usefulness

Use the Yandex.Metrica tool. They help you test the visitors' behavior on your site and, for example, identify weak pages.

Also, make sure that the pages relevant to the search queries:

Why does my site change its ranking in the search results?

The site ranking in the search results changes for various reasons, for example:

Reason Description
Search algorithms changed Ranking algorithms are constantly being updated in order to improve search quality.
The search database was updated Site characteristics are continually updated based on the latest data about the pages as well as their popularity among users. In addition, machine learning algorithms and ranking factors are regularly updated. As a result, positions in search results can also change.
There were changes on other sites included in search results for the queries you are interested in Your site's position in search results might change if other resources increase their relevance for the same queries (as owners of other sites also update them). If top positions in search are taken by suspicious sites, use this feedback form to report it.
The site URL changed After you change the site URL, its position in the search results may drop, since old pages disappear from the search index. If your site has a redirect with HTTP code 301 set up, check out the rules for processing it.
Pages that were previously in search results are no longer shown

To check if a page is included in search, use the Check URL status tool or enter a search query with the url operator (example).

To find out about changes to the page status in the search, use the Important page monitoring.

There are other changes on your site Any change to a site can affect its position in the search results. For example, updates the site structure, URL or the content of the page that matched certain queries.
Users' interests or needs changed The decision whether a site page will appear in the search results is made by special algorithms based on many factors. One of them is if the page can be interesting to users. If the algorithm considers that a page doesn't match queries, its position in the search results may decrease, or this page may not be included in the list of pages in the search.