Hi HN,
I'm currently designing a high speed gaming service which has a need for reliable mobile push notifications with accurate badge counting for when the user has the app killed.
So how are engineers on HN currently implementing push notification functionality into their apps and services that manage the badges counting, delivery and making sure the notification gets delivered to the user instantly with the correct unread badge numbers for each user.
Also very curious to know your server architecture, badge counting and design decisions on implementing this if you've done this before.
The matrix of devices to support and changing APIs makes it very complex to support this as a DIY solution.
If you are looking for instant notifications and the game can be in foreground then web sockets might be a better option.
You can look at an architecture posted by Uber sometime back that shows how they handle messaging at scale.