Real-time App Server Implementation

Hello, everyone

We are implementing app programming that shows the waiting time and number of people at a restaurant in real time.

As far as I know, database, server, app exists, so when data comes into the database, the server is responsible for

I'm posting this because I think it's a framework that updates the database by continuously updating the waiting time and waiting source, and the app only brings data from the database, and I want to ask you how to implement these real-time action servers.

I'm looking into node.js, so I'd appreciate it if you could post various opinions.