What do you mean by someone "less busy" than you?

@sf02 Usually those situations happened when I receive a communication that the position in no more available the day before the interview or even just an hour before: there is no time to inform the candidate. And here a candidate can be selected before all other scheduled interviews can take place, so sometimes I interview someone for a position already filled

@Bebs i usually work on 3 or 4 projects, both as developer and team leader, I have to take part to teams meetings, meeting with management, meetings with customer, I am not always in the office, etc. So for me lose 1 hour with a useless interview can be very difficult. A developer that work on a single project and is not required to take part to meetings can accommodate better with their schedule

Possible duplicate of What is a nice way to end an interview that is clearly going badly?

@espindolaa I don't think my question is a duplicate of that. The outcome of my interviews is not related to the candidate

@AlexQ I don't understand why you can't simply call the candidate, even if you only find out an hour in advance, and tell them that the interview is cancelled. I've had companies cancel on me on short notice, simply because people were busy / out sick / etc. What's the downside to calling, even an hour before the interview?

Further to @DaveG's comment, even if you only find out 5 minutes before the interview, you can still explain, apologize, offer tea, coffee, etc. and let the interviewee choose whether to stay and chat or leave immediately. Unfortunately, you seem to care about your own wasted time but not about the interviewee's wasted time.

This is basically an XY question where there is only 1 answer, OP knows that answer and mentions it but insists they don't want the 1 real answer and instead demand an answer that does not exist. This is the king of XY problem questions.

Welcome, Alex. You really need to bring this up with your HR department and help them improve their process. All of the reasons you list why the interview is pointless are valid reasons to NOT schedule an interview! If your HR is scheduling interviews for candidates with no possible job offer extended, they are wasting everyone's time.

You can practice your interview skills and try out new techniques and questions.

This reminds me of Dilbert. I think there was a strip where they tried various things to get the candidate to flip out.

Seems to me that you should be asking this question of HR, since they're the ones whose policy requires you to conduct these interviews.

please don't post answers in comments. Right now we have several high-ranked comments that should have been answers or one answer. These comments might be deleted thought

@dan-klasson a "senior technical team leader" in a company with a large HR department (by the sound of things) probably has no influence on the recruitment process, even if the HR department isn't up to the job

"2 days after a position has become unavailable". What does unavailable mean? If it's a verbally accepted offer, then you haven't really filled the vacancy yet. I'd also think carefully about giving offers if you have other interviews scheduled within the next two days. If it's a signed contract / new employee has started, then I'd expect you to have more than two days notice that this was likely to happen.

To me it looks like HR is having their performance measured by number of candidates interviewed per month/year, so basically they are gaming the system and wasting people's time and money, you have to fight that as expressed correctly in countless answers

I had my share of interviewing and I have to comment on your second edit. First, as commented and answered bellow, no it is not ok to summon an interview when you know it is irrelevant. second, I would tell HR that if this is their policy they can conduct such an interview themselves. I would not participate event to the point of me losing my position. Conducting such an interview will hurt my good name as a manager, employee, engineer, and a human being.

Let's flip that around. How about asking "I'm going to waste a few hours of someone's life. How should I do that?". The answer, of course, is "Don't do that".

I wonder if this might even approach fraud - you're costing someone time and money under false pretenses of having a job to offer. This is rather equivalent to selling lottery tickets when you've already handed out the prize.

@thelem: reading between the lines, quite possibly the company has an overly high reject rate in offers (possibly because it already has a toxic reputation, and/or lowballs on compensation), or else HR is driving its phony KPI into other depts' productivity, to conduct sham interviews (which will quickly earn it a toxic reputation) and managers are not able to push back on the unethical waste of everyone's time (more toxic reputation).

OP's edit regarding this is immutable policy is precisely why dolts who think policy and procedure is god think I hate process! I hate process that overrides logic in the name of not having to think. Hiding behind a horrid policy just because some twit who doesn't understand the ramifications of his attempt to appear fair is a terrible decision and entirely misses the point that an interview scheduled in vain doesn't have a single thing to do when the job was or was not available.

BTW, I worked at one of these megaliths where one building’s security got tired of people forgetting their badges so they created a policy stating that in order to receive a temporary badge, your direct manager must physically come and meet you at the security desk. This from a company that allowed managers to: take PTO, …work from home,… work staggered hours from their team,... travel… and often…have direct reports up to 4 time zones away. It took months to change because it was “policy”.