An SEO professional was concerned about a site migration they did. They did a CMS migration and changed all of their URLs entirely.
They made changes to their URL structure, etc., completed all of the required 301 redirects to the new URLs, and improved all of the technical aspects of the website.
However, they found that traffic dropped significantly, immediately after the URL changed.
John explained that when one domain is moved to another, Google transfers everything to the new domain very easily.
If you change all the URLs in the site, though, that does take more time for processing. This is because with all the URL changes, Google cannot transfer the entire site in one direction.
Instead, Google has to reprocess the entire site and understand the exact context of all the pages on the site first.
This can take quite a bit of time.
It’s likely that during this period of flux that you will see fluctuations in ranking. It’s also possible that the flux period could go on for a longer duration.
This is the problem with changing the entire CMS. Oftentimes, CMSes have specific attributes that get removed – or otherwise – as a result of such a migration to a new CMS.
For example, from WordPress to Drupal.
This also includes many things surrounding internal linking. Things like changing the design of the pages, changing the internal URLs, and others.
These types of changes are all things that can cause significant ranking and traffic drops as a result.
Furthermore, because of these changes, it’s possible that the final state of your site is something less than it was before, hence the reason why it lost many of those rankings.
It’s important to understand the differences between the older version of the site and the new version, so that you can make any necessary adjustments.
Sadly, waiting to see what happens is part of the job and you have to do this in order to see what kind of impact will occur after these types of changes are in full effect.
This happens at approximately the 32:45 mark in the video.