How are the site folder rights set for the www-data user?

Question

Nginx

I’ve been sitting for 2 hours thinking how to do it right, you need to set the rights of the folder.
There are 2 users www-data and ftp.
How to make it more correct, so that FTP could set the rights or create a file and so that the security would not suffer?
The www-data user has set the www-data group to the folder
/var/www/
The FTP user has been placed in the www-data group and set group rights to the folder / The
cmod 770 /var/www/
question will be correct in this scenario with several sites?
/var/www/site.ru
/var/www/site2.ru
/var/www/site3.ru
I'll reformulate the question what rights for www-data should be set on the folder with sites I think that these will do?
chmod -R a-rwx,u+rwX,g+rX /var/www owner and group www-data.
How to make ftp user with the same rights as www-data without group intervention?

Answer 1

Can create a user for each site and give them access to sFTP (prohibiting ssh)?
Then the files themselves will be recorded with the user and group of the site.