def json_utf8_decode(obj: object) -> object:
    """Decode all strings in an object to UTF-8.

    :arg obj: Object.

    :returns: Object with UTF-8 encoded strings.
    """
    if isinstance(obj, bytes):
        return obj.decode('utf-8')
    if isinstance(obj, list) or isinstance(obj, tuple):
        return [json_utf8_decode(item) for item in obj]
    return obj