Imagine you are developing a feature for an application that tracks **user interests**. Information about each user is stored in **Redis** as a **set**. Each user has a unique collection of **interests**.

1. Add the **interests** for each **user** to their respective **sets**:
    - `user:1:interests`: "**music**", "**movies**", "**sports**";
   - `user:2:interests`: "**sports**", "**travel**", "**reading**";
   - `user:3:interests`: "**reading**", "**music**", "**cooking**".

2. Check if **User 1** is interested in "**travel**" and if **User 2** is interested in "**sports**";
3. Identify the **common interests** of **User 1** and **User 2**;
4. Find the **interests** of **User 1** that are not shared by **User 2**;
5. Create a list of all **unique interests** shared by **User 1**, **User 2**, and **User 3**;
6. **User 3** has stopped being interested in "**music**." Remove this **interest** from their **set**;
7. Display the list of **interests** for each **user** after performing these operations.

**1**. Add **interests** for each **user** to their respective **sets**:

```
SADD user:1:interests "music" "movies" "sports"
SADD user:2:interests "sports" "travel" "reading"
SADD user:3:interests "reading" "music" "cooking"
```

<br>

**2**. Verify if a specific **interest** exists in a **user's set**:

```
SISMEMBER user:1:interests "travel"    # result: 0 (User 1 is not interested)
SISMEMBER user:2:interests "sports"   # result: 1 (User 2 is interested)
```

<br>

**3**. Retrieve **shared interests** between two **users**:

```
SINTER user:1:interests user:2:interests   # result: ["sports"]
```
<br>

**4**. Get **interests** of one **user** that are not shared by another:

```
SDIFF user:1:interests user:2:interests   # result: ["music", "movies"]
```

<br>

**5**. Create a full list of **unique interests** from all **users**:

```
SUNION user:1:interests user:2:interests user:3:interests   # result: ["music", "movies", "sports", "travel", "reading", "cooking"]
```

<br>

**6**. Delete an **interest** from a **user's set**:

```
SREM user:3:interests "music"
```
<br>

**7**. Retrieve the updated **sets** of **interests** for each **user**:

```
SMEMBERS user:1:interests   # result: ["music", "movies", "sports"]
SMEMBERS user:2:interests   # result: ["sports", "travel", "reading"]
SMEMBERS user:3:interests   # result: ["reading", "cooking"]
```

Learn how to implement and configure caching in Spring Boot applications using Redis. Explore Redis integration, Spring caching annotations, and practical strategies for managing cache and improving application performance in backend systems.

Challenge: Managing User Interests