def _is_valid_password(password: str) -> bool:
    """Check password length + at least one uppercase + one digit"""
    if not isinstance(password, str) or not password.strip():
        return False
    if len(password) < 8:
        return False
    if not any(ch.isupper() for ch in password):
        return False
    if not any(ch.isdigit() for ch in password):
        return False
    return True