An on-the-spot interview is an interview that is conducted on the spot, without any prior notice or preparation. This type of interview is usually used to fill a vacant position that has just opened up, or to fill a position that will become available in the near future.

The main advantage of an on-the-spot interview is that it allows the employer to get a feel for the person they are interviewing, without giving the person time to prepare or rehearse their answers. This can give the employer a better sense of the person's true character and capabilities.

On-the-spot interviews can also be used as a way to screen candidates, by weed out those who are not truly interested in the position or who are not a good fit for the company.

The downside of on-the-spot interviews is that they can be very stressful for the candidates, who may not be expecting or prepared for them. This can lead to candidates giving less than their best performance, which is not an accurate reflection of their true abilities.