Wordpress developer

We are looking for a remote work wordpress developer from Minsk.
The project is a popular torrent resource operating in CIS countries as well as abroad (USA, Spain, France, etc.)
Tasks:
1) Connect a new payment system
2) To make a couple of new pages (peywall)
3) Simplify the process of buying a premium (changes in old pages, layout and integration of new pairs in order to reduce the number of steps)

To solve the problem with performance, the site in peak hours noticeably slows down.
Also, the mobile version needs to be corrected.