E-shop + App = What bundle of platforms does your company use?

Question

CMS

What is used in your company or by you personally to create a link between the Online Store and the Application to it? Only practitioners who have such production on stream are interested in the answers.
I would be grateful for the details:
Backend
- What CMS or PHP framework?
-What DB?
-How do you solve the problem of linking with 1C?
-How do you solve the problem of payment systems?
-Flexibility: is it easy with this configuration to do any unique things for the customer (complex algorithms for calculating something (furniture designers in JS, as an example) related to the database.
Frontend
-JS and CSS frameworks -What
complex tasks did the customer have to deal with? collide, how they were solved within the framework of this bundle
?
-Native PL or Webview?
-Give an example of a finished application - see)

Answer 1

1c-bitrix

Answer 2

UMI.CMS

Answer 3

c gator