How are online stores built like citylink and dns?

Question

CMS

Good day
Recently I paid attention to online stores citylink and dns. They are visually almost the same for the consumer and the consultant in the store, with access to warehouse balances and fast (not the site itself, but everything)
In the DNS, the consultant, with the same simple interface and high speed, checks the
balances before payment
. And now the question is
On what principle are such systems built? A single database, local versions (most likely, everything does not work through a single server, it would slow down),
Did they develop the engine themselves or cms, a framework?
Dealt only with simple CMS. I'm thinking of leveling up

Answer 1

I'll tell you a secret: the usual CMS such as Joomla (and derivatives) plus 1C and that's it. Sellers work through 1C, after changes (or by time) they upload data to the site.

Answer 2

Citylink is a completely self-written move from the first line. Data is uploaded automatically or at the request of the client (employee). CSNs are never similar at all) especially from the inside.

Answer 3

DNS uses many different technologies written in PHP Yii framework, Vue Js Nginx web server is used on the front. In general, there is a whole bunch of technologies from both Google and Facebook and the Ruby token are used, in general, a lot of things, you can’t build this in one helmet.