Any backend engineer here who has worked on an app used by millions at scale?

Hey Grapeviners Is there anyone on this platform who has worked as a full stack dev/architect/ backend engineer for a mobile app which caters to users ranging in few hundred thousands to millions..

I want to connect with someone to understand few things for an idea I want to purse..

Would love to have an open discussion with an enthusiast!! Please comment here or reach out to me at codenerdai@gmail.com