Comment by rmbyrro

Isn't this simplistic?

It really depends on the service, how it is used, the shape of the data generated/consumed, what type of queries are needed, etc.

I've worked for a startup that hit scaling issues with ~50 customers. And have seen services with +million users on a single machine.

And what does "quickly" and "popular" even mean? It also depends a lot on the context. We need to start discussing about mental models for developers to think of scaling in a contextual way.