Effective Whiteboarding during Programming Interviews

It has become the quick way for validating whether a candidate is suitable for the job or not. Some companies now go for tech-screens where they'll send you a problem to solve on the computer, but that's rare.

When a candidate is solving a problem on the whiteboard, an experienced interviewer can make a good judgement. In my experience, anyone who's a good developer does well on the whiteboard. However, the inverse is not always true.