I am working on a major upgrade of an online shop that includes both migrating to another CMS (page design will change a lot) and rewriting articles describing the kind of product that is sold. A couple of articles have notable SEO effect and I want to preserve it or at least not to vaporize completely. As I understand, these are the things that I can and should make the same on pages with rewritten articles served by the new CMS:
- The most SEO-successful sentences that are shown in snippets of search engines (there is a one such sentence in each article)
Another thing I consider is making a gradual updating of a website, so that I first put rewritten articles in the old CMS, wait for these pages being reindexed and then change CMS. Does this two-step process make any sense? Will search engines be less "shocked" because design and text content will evolve gradually?