With the help of what is the internal component of these sites E-Autopey, Glopard, Ecomtools made?

Question

PHP

Inside these sites
is - a system for receiving and processing orders.
- affiliate program each owner of an online store can connect partners to his site and track and accept orders through partners. links
- the ability to send mailings to your customers
- add and customize products, both physical and info products
- order form constructs, etc.
I am interested in:
1) what they are made
of 2) when creating such a service, where to start
3) how difficult it is
4) how to secure such a project

Answer 1

1) Made using some kind of server-side programming language. Client logic ends with local jquery and bootstrap
2) It is necessary to begin the similar project with TK. Acceptance of payments, in particular, begins with the fact that they are looking for a bank that will shelter you.
3) Depends on the heresy that you write in the TK. But in any case - the conclusion of agreements with banks and payment systems, as well as testing for compliance with security requirements - these are months of fuss and boring paperwork.
4) Depends on what you actually want to secure.