The Builder design pattern allows us to create immutable objects with a large set of state attributes. Let’s go over some more reasons on why do we require this pattern: 1. We don’t want to create a chain of contractors. 2. We don’t want to create the constructor with too many parameters as it will be difficult to manage from client code and it creates confusion like ordering of arguments. 3. We don’t want to pass with optional arguments to constructors as NULL. We don’t want to build such a complex object using a factory pattern.