Welcome back! We're moving on to the next essential part of our Redis-based backend system project — handling transactions with pipelines. This will help us execute multiple Redis commands as a single atomic operation. Remember, you've already gotten comfortable with managing user data and leaderboards. This unit will take it a step further by optimizing these operations using pipelines.

Before we dive in, let's recap what you’ll be focusing on in this unit. The key tasks include:

1. Adding user data with expiration using pipelines: We will group multiple commands into one pipeline to add user data more efficiently.
2. Adding scores to a leaderboard using pipelines: Using pipelines to add scores will ensure these operations are atomically executed.
3. Executing the pipeline: We'll ensure the grouped commands in the pipeline are executed together.

These tasks will help us understand how pipelines can enhance performance and consistency in our Redis operations.

To add user data with expiration, we use the addUserWithPipeline method from the User class. This method takes a Pipeline object and ensures that user data is stored with an expiration of one day: