Development of a modern messenger, choice of technologies: React-Native and Node.js?

Question

Mobile development

Hello!
The task before our team is the following:
Develop a messenger, clients for Android and iOS, server ??? possible and ready to deploy and templates, from scratch last,
Functions chat, audio chat, video chat ... encryption ...
with the ability to scale further in terms of download and number of users
There is a question of choosing technologies:
client - React-Native - audio and the video can tell me where there are examples or components ...
native languages ​​\u200b\u200b- there are examples somewhere, maybe also throw links to look at modern ones, but then writing for both platforms separately, long, inconvenient.
Missing components are written natively, the rest is simple in react-native. Interesting, but again, you need skills to write for both platforms - a complication ...
Server - php or node.js or something else, tell me, also links to examples or libraries with components ....
In general, I want to start with a simple one - are there any ready-made servers and clients without problems with large licenses and which can be added with their functionality?
If there are none, which I doubt, then templates and technologies on which it is better to develop.
I will be grateful and should for everything that tell me sensible))

Answer 1

I can talk about my experience.
I did on cordova version for ios and android + web version.
I delivered messages using web sockets on a bundle of php (for business logic) and CppComet for working with web sockets.
I made video chats on webrtc based on the integration of CppComet with FreeSwitch (minimal demo of video chat and github )
As for the load, here are the results of CppComet load testing, but how fast your business logic will work depends on you.
Regarding scaling to more than one server, there should also be no problems with the comet server.
As for the quality of the application, as for me, it depends primarily on the directness of the hands and not on the fact that you have React-Native, real-native or webview from cordova. If you correctly design the interface and do not overload it with many elements, then it will be very difficult to notice the difference in performance. Moreover, it is not difficult to write native plugins on cordova, so at any time you will have the opportunity to perform some of the really complex operations in native.
CppComet is my own open source project so if there are questions we can discuss.

Answer 2

Do with those technologies that you personally know best.
Highly loaded services such as Facebook or VKontakte are based on "antediluvian" PHP.
It's not about the technology, it's about your ability to use it.
PS:
React-Native is originally a substitute technology.
Suitable for quick creation. If that's your goal, then fine.
But for a better solution, I would choose not React-Native, but real-native. It's more expensive, longer. But it works better in the end.