Quick App Pus Notification - IOS/Android.

Hello Freelancer, *Please provide RELEVANT description in your bid to show your ability to provide the requirements. We have Joomla platfrom that sends push notification to IOS/Android app users, Our service is basically a REAL time notification, so all what we care about is delivering our notification in max 15 seconds. We noticed a 1 -3 minutes delay when sending to 5000 users using our current code (As attached). I am open for any solution to make the notification FAST in terms (i.e : changing the sending code OR using external services OR Multi threading platform) Our requirements: Enable our system to send 20,000 notifications where 100% of users receive the notification in less than 30 sec..