Welcome! In this unit, we will delve into implementing Pub/Sub for notifications within our Redis-based backend system project. You've already learned how to manage user data, handle transactions, and use streams for event logging. Now, we'll add another powerful feature to our project: real-time notifications using Redis Pub/Sub (publish/subscribe). This will enable our system to send and receive messages instantaneously.

In this unit, we'll focus on creating a simple real-time notification system using Redis Pub/Sub. Specifically, we'll cover:

1. Publishing Messages: How to send notifications.
2. Subscribing to Channels: How to receive and handle notifications.

Let's quickly refresh how Pub/Sub works in Redis using JavaScript and ioredis:

In this JavaScript code snippet:

1. The publishMessage function publishes a message to a given channel.
2. The messageHandler function handles incoming messages from the subscribed channel.
3. The subscribeToChannel function subscribes to a specified channel and listens for incoming messages.

Exciting, isn’t it? Now, it's time to put this into practice. Let's implement the complete code to build our real-time notification system. Happy coding!