How dangerous is the transfer of a site from one CMS to another in terms of changing positions in search engine results and how to avoid negative consequences?

Question

Search Engine Optimization

There is a site on CMS, due to certain reasons it is necessary to transfer it to another CMS.
For some key phrases in Google, the site is on the fourth or sixth page. I think this is not the worst result, but the question is how the search engines will react to replacing the CMS and how to prevent deterioration. In addition to the fact that you need to keep the same texts for the same links, what else needs to be taken into account in order not to worsen the position of the site for key phrases in search results?

Answer 1

How dangerous is the transfer of a site from one CMS to another in terms of changing its position in search engine results

100% dangerous if you don't know what to do or don't do what you need to do.

and how to avoid negative consequences?

Below is what you need to do, in addition to what other users recommended to you (saving the URL structure, etc.).
Programmer :

1. Close the test domain from indexing;
   
2. Before transferring, make a backup of the old and new site (files, database);
   
3. If the old site already has its own redirect table (for example, in the htaccess file), transfer it to the test site.
   
4. Leave the verification files of the Google and Yandex webmaster panels in the root directory of the site so that access is not lost during the transfer;
   
5. Before day X, all information on the site needs to be synchronized. These are prices for goods (services), and statuses (available, not available);
   
6. Transfer content from the old site to the test site (texts from individual pages (contacts, about us, etc.), sections and categories pages, texts from pages of optimized filters (if any), not only text, but also video, pictures along with ALT As well as all information from service pages, article pages, service pages or blog;
   
7. In the robots.txt file, specify directives that prohibit indexing for the technical pages of the site, as well as a link to the XML sitemap;
   
8. Re-generate the sitemap.xml file so that it contains the pages of the main site, and not the test one;
   
9. All internal links (menus, links in texts, links in the next, prev, canonical attributes) must be relevant - not belong to the test site;
   
10. Move meta tags to new pages (title, description, keywords, H1)
    

To an SEO specialist after transferring a test site to a production site :

1. check the response codes of previously unloaded pages and service pages, blog pages, news, and so on, subdomains, if any.
   
2. check robots.txt;
   
3. table redirect settings;
   
4. Presence/absence of a tag on landing pages;
   
5. The presence of meta tags and duplicates;
   
6. Update sitemap.xml files in Yandex/Google webmaster panels
   
7. Conduct an SEO site audit
   

General:

• warn specialists who work with contextual advertising or advertising in social networks that the URL will be changed and will be transferred to a new CMS.
  
• Also, specialists should clarify which codes they need to transfer.
  

Site administrator:

• selectively (or in a row) checks for the presence of texts on the test site (compiles a table: URL of the old site, Page title, Text (yes, no), What to do (transfer, moved), test site URL)
  

Answer 2

The fourth sixth position is the bottom, there is no point in worrying about the positions, you make the right transfer and that's all.