Sending FCM Push Notifications with Andpush Gem
Recently, I had migrated from GCM (Google Cloud Messaging) to FCM (Firebase Cloud Messaging) because GCM was ending its life.
At first, I found fcm gem which supports FCM. I changed my application code to use the gem and I deployed the new version since it was working nicely on the staging. However, as time goes, I realized that FCM notification sometimes stops working when the application runs on multiple threads.