I am curious about real-time message handling for user-customer(buyer-seller) situations. I am well aware of that, most of the time it’s handled either web socket or async(Kafka) + cache(Redis). But how exactly are they handled in real-world applications like UpWork, Fiverr, etc, client, server, or hybrid? I am trying to build a simple app for a demo with react + Spring Boot, as I mentioned, we can achieve it in both ways(server or client), but what is the safe and suggested way to implement it?

I am thinking of handling WS connections – routing, etc on Serverside (Spring Boot) and changing UI – passing messages to channels, and showing them on UI on Clineside(React).