SEO Audit – the transition of the site to a new system

The theme is elite real estate in the SPB. The competitive niche.
The trust site decided to move to a new engine so that the site works better and faster.
I worked in a couple with another cousin. I consulted a group of programming professionals who are working on the new project.
As a result, after moving the site did not lose its positions - but only grew up in times.
I gave advice on the internal architecture of the site, linking, optimization of images, writing content.