How do large online stores work?

Question

1C-Bitrix

In general, I wondered how large online stores work.
Most large sites use 1c-Bitrix, and 1c is most likely used for keeping records (which I know very superficially) ...
Therefore, the question is brewing, what do call center managers / operators use? Where are all orders created and processed? Perhaps they use CRM, but the same Bitrix24 does not seem to work very well in conjunction with an online store (to place an order, an order is opened from 1c-Bitrix, which is very long and inconvenient)

Answer 1

Everything is done custom, its 1s and its Bitrix, everything is very convenient and fast.

Answer 2

1C-Bitrix is ​​good for a quick start. Integration with 1C out of the box. We have our own CRM.
Of course, you can write everything yourself, just for your Wishlist and needs, but this is a longer and more expensive process.