[avl999]

That is extremely unprofessional and a bad look for the interviewer. I have done over a 100 interviews including some really bad ones, never have I ever cut one short. When you are interviewing you are representing the company, whenever I interviewed someone even if I knew it was going to be a clear no, I tried to make them feel good about the process as what that person is going to go out and say directly reflects on the company and future hires. 20 mins of your time is a drop in the bucket in terms of impact of getting a bad reputation, not only are you potentially shooting yourself in the foot with other candidates but leaving a bad taste in the mouth of the one you are interviewing who might in the future would otherwise reapply at a different stage in their career if/when they become a stronger candidate.

[BubbleRings]

Yes, I'd like to order a few truckloads of people like this guy for the workplace please.

And yes, I still name the company when I tell the story of my worst experience interviewing at a company, 30 years ago.

[throwyuno]

Hm, sometimes when I’m interviewing someone who I know is a “no” it feels like I’m leading them on if I go through the full interview. I thought it would be more respectful of their time to let them know that early, but maybe I am wrong about that?

I’ve also heard (via HR) about candidates being surprised to not get the offer in cases where I kept the interview going and pretended things were going well.

[avl999]

The interviewee already has their schedule booked off during that window, that extra 20 mins is not saving them any time. If your concern is their time, I would assume they'd "waste" more time stewing on an early interview exit and thinking about it rather than if it just ended normally.

[LegitShady]

Finish the interview, and provide feedback if asked why it was a 'no'.

Interviewing isn't just for fun, and even if you don't get the job, you can go through the interview to practice, and hopefully to figure out what went wrong.

If after 20 minutes they just say 'I think this is a no so go home' I wasted a lot more than 20 minutes and got nothing out of it.

[kyawzazaw]

Providing feedback is usually not a thing because of liability.

[christophergs]

I agree that ending an interview early is a no-go. However if it's an onsite/process with multiple interviews, I think the fairest approach (and I've done this in the past) is to manage expectations ahead of time that the full interview sequence only happens if you pass each one.

This way you don't waste the candidate or your time if it's clearly a no after interview 1. They feel a bit bad because they obviously didn't pass, but if you've communicated ahead of time it's not a rug-pull.