On the backend: using MySQL database for data storage; using Redis data storage for keeping cached data and user sessions, manual and performance testing, creation of server monitoring settings, integration with payment systems; plus FCM integration for subscriptions and push notifications.
On the WEB side: creation of WEB interface for various user roles, slow internet connection support, offline mode, setting up the functionality for sending SMSs in different countries.
On the API side: localizing the system interface into different languages.
In addition to the solution, we've developed BeED
promo website.