Doctors are continually interviewed every time a patient gets pissed and sues them or files a board complaint. If there's any fault they're (very publicly) assigned remedial training or put on a PIP. They're also in incredibly high demand, so its often the doctor interviewing the practice.

If the interview is for becoming a partner at a practice, it's a two way courtship that's more reminiscent of other businesses looking for a co-owner.

Doctors also tend to hear about each other. Even in decent sized metro areas, they can often know who to avoid.

(This process isn't perfect, but it's still way different than for software.)