Shakes while braking

4 wheel disc or with rear drum brakes?

What exactly was done for the brake job?

4 wheel disc and I just had the rotors changed. Brake pads were checked and still in perfect condition.

Very rarely do I not replace the pads when replacing rotors. Penny wise, pound foolish. Warped rotors compromize brake pads. To do the job right, the pads must come off anyways. The caliper needs to be checked, the slide pins removed, cleaned and lubed. The thin metal clips that the pads rest in also need to be removed, cleaned and lubricated. If not the reason the rotor warped in the first place may very well still be present. E-brake should also be checked for proper operation.