from typing import Tuple


def get_overlap(bb1: Tuple[int, int, int, int], bb2: Tuple[int, int, int, int]) -> float:
    """
    Computes the overlap between two bounding boxes. 
    Returns the ratio of area between bb1 and the intersection of bb1 and bb2.
    """
    intersection = [
        max(bb1[0], bb2[0]),
        max(bb1[1], bb2[1]),
        min(bb1[2], bb2[2]),
        min(bb1[3], bb2[3]),
    ]

    if intersection[0] > intersection[2] or \
        intersection[1] > intersection[3]:
        return 0.0

    area_bb1 = (bb1[2]-bb1[0])*(bb1[3]-bb1[1])
    area_intersection = (intersection[2]-intersection[0])*(intersection[3]-intersection[1])

    return area_intersection/area_bb1