Pattern Prototype

The prototype pattern belongs to the group of generative design patterns.
Let’s say we are developing a dating app Tender, according to the business model we have a paid option to make copies of your own profile, changing the name automatically, and the order of the photos in some places. This is done so that the user can have the opportunity to manage several profiles with different sets of friends in the app.
By clicking on the button to create a copy of the profile, we need to implement copying of the profile, automatic name generation and re-sorting of photos.
Naive pseudocode implementation:

fun didPressOnCopyProfileButton() {
    let profileCopy = new Profile()
    profileCopy.name = generateRandomName()
    profileCopy.age = profile.age
    profileCopy.photos = profile.photos.randomize()
    storage.save(profileCopy)
}

Now let’s imagine that other team members copy-pasted the copy code or came up with it from scratch, and after that a new field was added – likes. This field stores the number of profile likes, now you need to update *all* places where copying occurs manually, adding the new field. This is very long and difficult to maintain the code, as well as to test.
To solve this problem, the Prototype design pattern was invented. Let’s create a common Copying protocol, with a copy() method that returns a copy of the object with the necessary fields. After changing the entity fields, you will only need to update one copy() method, instead of manually searching and updating all the places containing the copy code.

Sources

https://refactoring.guru/ru/design-patterns/prototype