I originally built my app in firebase but my app is scaling beyond its current capabilities very quickly. I am running into an issue with how to sync data such as firebase does. My plan is to make a call to a PHP script which interacts with my MySql database (switching to relational). Where I am lost is how to monitor changes to the database. The biggest draw for firebase is its real time capability for me. I want to receive changes when records are updated/removed/added/moved etc. What technologies are behind doing something like this and how to execute? MY app is built using Swift.