def is_valid_gatech_username(username: str) -> bool:
    """
    Rough validator for GT usernames

    :param username: the username to check
    :return: whether this is a valid username
    """
    if not username.isalnum():
        return False
    if not username[0].isalpha():
        return False
    if not username[-1].isnumeric():
        return False
    return True