Can you remind me why this is necessary to do in C++? I'm sure there is a good reason, I just don't remember reading the reasoning. (It can be good to include this info in the diff description, or maybe a link to this info if it was previously covered on a diff or Linear.)

Probably the answer is from my line in the Linear issue:

On native it's important that the ID be accessible from outside of JS, so we probably shouldn't store it in Redux.

This seems like part of the story, but it's still possible for the ID to be generated inside JS but accessible outside of it. Why do we need to generate it from C++ instead of JS?

I talked to Tomek, and the reason for this decision was that we don't yet know, where the code will be called from. We thought we might want to call the function for example when: the user is logged, he updated the app and before he opens it again a notification comes. So it has been written in c++ to give us flexibility. Is this a problem?

That's reasonable, thanks for explaining @inka! The reason I asked is that it's generally better to implement in JS than in a low-level language like C++... JS is more simple, and more people on the team know JS. That said, in this case I can understand the reason for using C++.