[close04]

> I'm not looking for candidates to show that they care

I'm sure gut-punching you also doesn't change the fact that they can think about algorithms and code. But it does say something about them as people and their character. Showing they put effort in preparing for the interview suggests they put effort in preparing [period]. I've seen plenty of exceptionally qualified people that were a net loss for any team due their attitude. I imagined that as an interviewer you already saw that interviews consist of more than just technical skills (there were probably other people in that panel looking at those other things specifically).

In life, and interviews, it's not just what you say but also how you say it. ;)

[jefftk]

I think gut-punching your interviewer is a strong negative signal about how it would be like to work with you, but wearing informal clothing is not much of a signal at all. There are just so many different reasons someone might be dressed that way: they could be the kind of person who doesn't put effort into things, they could think dressing up for an interview is cheating, they could not care about clothes in general, they could have been going off of advice to "wear something comfortable".

Similarly, if the candidate brings their own water bottle vs asks for a drink you could say that this is good because it shows them being prepared, but I think all of this is just too noisy to read anything into.

(I do think in other fields things are different. I'm just talking about programming here.)

[close04]

Are you wearing flip-flops when you interview them? Do you tell them in advance to feel free to wear flip-flops?

> but wearing informal clothing is not much of a signal at all

You just moved the goalposts. I didn't say "informal is a problem". I said "jeans and sneakers already is the lowest reasonably acceptable way to dress for an interview" and "flip-flops or anything like that would definitely fall below just underdressing". This signals that you may believe you are too good to wear for an interview anything more than you'd wear when taking out the trash. And believe it or not that's exactly what myself and so many others noticed in practice. Many of those people do actually turn out to be very good, maybe even some of the best in the team. But as I said above they were finally a net loss for any team specifically due to this attitude.

And yes, bringing your own bottle of water would be the norm if asking for one was seen the same as asking the interviewer for a pair of decent footwear ;). Is it the same?

> they could think dressing up for an interview is cheating

Wearing jeans and sneakers instead of flip-flops and trunks is not "dressing up" in anyone's book.

You're taking the most unreasonable interpretation of everything (not just as hyperbole like my gut-punching example) and moving the goalposts just to make your point.

[jefftk]

> Are you wearing flip-flops when you interview them?

Yes, in the summer I wear flip flops when I interview people. Flip flops and shorts are within the range of regular informal clothing at my workplace, and people don't dress differently on days when they're interviewing people.

> Do you tell them in advance to feel free to wear flip-flops?

I don't talk to them in advance of the interview. I'm not sure what recruiters/friends/etc tell candidates about what's customary, but I do think many people get advice like "you don't have to dress up, wear whatever you normally do".

> You just moved the goalposts.

I'm not trying to move the goal posts. I'm still talking about flip flops and shorts.