How not to lose positions in the PS after updating the site and switching to another CMS?

Question

Google

There is an old site running on an old version of UMI.CMS , the domain is over 9 years old .
TIC: 60 , Yandex Rank: 3 out of 6, added to Yandex.Catalog
Indexing:
Yandex: 594
Google: 530
Site number 1 in Yandex and Google for thematic queries in the region!
Now we have prepared an updated version of the site based on WordPress , the content will be the same, but here is the structure of the sections and resp. links will change. It is clear that there will still be a failure in terms of SEO, but what can be done additionally to somehow mitigate the fall in the position of the site in PS? Do you need redirects from old URLs to new ones - there will be hundreds of them ...

Answer 1

Redirects - yes, they are needed. Visitors must go exactly where they were going.
But still, with a code change, even with exact redirects, the site will be rescanned and stressed for the page rating. Most often, such things go in the negative, alas.

Answer 2

Make a map by redirecting from old urls to new ones. Further, of course, there will be a drawdown, but if the gluing of old and new pages goes well, then the positions will partially return.

Answer 3

As far as I studied the issue, many write (in principle, this is logical) when transferring / changing the engine, there will be a drawdown. In addition to 301 redirectors, comrades for saving results in search engines, bother and save articles, keys, etc., even urls, which is new for me! was to hear. In addition, they give Yandex and hum the correct settings so that they correctly understand that the site (like a mirror) and correctly indexed ... Write about the results, it will be interesting to read, I subscribe to the question)

Answer 4

After a little more than 2 months, the results:
- redirects worked - everything is fine.
- site lost in TIC-10
- traffic from PS by Metrika didn't decrease at all
Normal flight, still the first in the region for key queries!