Notification in node.js?

Question

MongoDB

We have a user, if an order is created for him, then inform him about it in real-time. Please tell me how to organize it.

Answer 1

On the client https://learn.javascript.ru/websockets
On the server https://www.npmjs.com/package/websocket
Socket.io is absolutely not needed for anything these days, web sockets work everywhere without crutches.

Answer 2

The simplest thing is that the client sends a request to the server once a minute to check if there are notifications for it.
And for good - websockets.