Amazon Frontend Engineer System Design Questions

Class Signature

class VirtualDOM {
    def create_element(self, tag: str, props: dict, children: List[Union[str, 'VirtualDOM']]) -> None:
        # Create a virtual DOM element
    def diff(self, old_tree: 'VirtualDOM', new_tree: 'VirtualDOM') -> List[str]:
        # Compute the difference between two trees
}

Example Method Signatures

• create_element(tag: str, props: dict, children: List[Union[str, 'VirtualDOM']]) -> None: Creates a virtual DOM element.


• diff(old_tree: 'VirtualDOM', new_tree: 'VirtualDOM') -> List[str]: Returns a list of operations needed to update the DOM based on differences.

Example 1:

Constraints:

• 1 <= number of elements in tree <= 1000


• Tags and props are limited to valid HTML attributes.