> interrupting me/talking over me, talking down to me, comparing their last junior position to being Steve Jobs, being sing-songy, inappropriate jokes in any way/shape/form, getting in arguments with themselves... etc etc.

Besides being "sing-songy", none of these things are quirks, they're ineffective communication or untruthfulness of their past positions.

As far as dress and "sing-songy" go, I would agree with the above poster: software development tends to be much more inclusive of these sorts of characteristics. Jeans and a T-shirt is perfectly acceptable attire for an interview. Do your software devs wear suits 5 days a week? Why expect a candidate to do so, either? A candidate I interviewed going, "uh-oh sphaghetti-oh!" when they hit a segfault when running their interviewing solution was kind of ridiculous, but ultimately has no impact on their contributions as a developer. Factoring in these kinds of thins into the hiring decisions is ultimately about including people from a culture similar to your own. Different cultures have different definitions of "weirdness" so selecting based on the ability of the candidate to identify what is "weirdness" is ultimately a cultural litmus test. And expecting male candidates to be shaved, as per your other comment, is just blatant cultural discrimination - some demographics like Sikhs could even sue you for illegal discrimination over this. This cuts both ways, both the case where a candidate in a T-shirt and jeans gets rejected for not wearing a suit and when a suited up candidate gets rejected for being too formal. Both ultimately hurt the company by excluding effective workers.

What is "dressing appropriately". I wore a suit to my very first interview for a dev position and very nearly didn't get the job because they were worried I wouldn't fit in (luckily I was able to explain that I don't usually wear a suit). The other ones in your list, sure. But I don't think those are what people typically means when they talk about quirks.

Yeah - I hate this. I had people at my last position give candidates negative points because they wore a suit and I went $%&#ing ape. In positions that I've held in the past it's been the appropriate action to wear a suit due to heavily corporate environments, and I see it as 110% normal that someone puts on a nice suit for an interview. The action of wearing a suit (or tie for that matter) to an interview should never be seen as a "cultural fit" problem - I'm looking at you SV...

Sorry that almost happened to you. That's some bullshit.

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Overall a nice well-fitting button down + a pair of well-fitting dress slacks is what I would recommend. Personally, I wear a slim fit brand new white button-down (ironed), nice dark blue chinos (ironed, not pleated), and not-scuffed brown wing-tips. Often I also wear a tie, but am considering not thanks to a derelict SF "big-wig" grilling me in an interview as to "why are you wearing a tie?" All I wanted to say is "does it matter?" (offender: you're reading this don't do that again.)

Also get a solid hair cut, ensure you're shaved if male, and yeah - sit up and be confident while you're in the chair. Body language does matter, and your interviewer will subconsciously notice regardless if they're giving you a "pass" or not.

I would agree and would go as far to say that dress in general should never be a hiring criteria for a non-customer facing position. Unless there are hygiene issues or they are wearing something actively offensive.

Unfortunately, our industry has no such thing, so I always ask before an interview. So far the answer is always "uh, we just wear normal clothes", "casual is fine" or once "just wear clothes, please, this isn't quite Burning Man" (ended up working at the last place), but: this was in the Bay Area, so YMMV.

Dress code doesn't really factor for me, but I've worked for the same place for a while now and we've always been 95% remote. Half of us just wear whatever we slept in the night before. Most people don't get dressed until lunch time. Even in the office it doesn't get much fancier than a t-shirt and jeans. I guess our tech lead wears a button down shirt, but his jeans usually have giant holes in them, so I would call that a wash.

Expecting an interview candidate to wear something nice would feel a bit hypocritical.

It seems to me that you're making an assumption about what is considered professional dress. I feel like it's fine to have such expectations, but you should express them clearly in the invitation to interview. It's not a case of "not bothering" if you have never expressed that preference in the first place.

-- "Sasquatch"

If you're completely unsure, just call the hiring manager and ask. "What's the dress code at company X?", "How do people in role X normally dress at your company?". No one will be mad at you for making an effort and trying fit into the culture.

I sort of twigged that I was over dressed when on the way to the interview some one stopped me in the street and asked me the way to the "Ivy"

Yep, I’ve been that guy! Had huge problems for a while. Mercifully my team/department/business put up with me for the most part, but I did have to suffer for a while. Learnt some invaluable lessons though and I’m quite happy to be a fitter happier and more productive individual! (Yes Radiohead reference but really not as bad as it seems:)

My response from the other side of the table: as an interviewee, I view these initial interviews an an exercise in expectation management. I don't consider myself as weird, so I act like I normally would, otherwise I'm setting myself up for failure later on.

Also, I don't wear to an interview what I wouldn't be comfortable wearing on a normal working day. I dress casual on purpose (but representably casual, not weird casual -- but that's my personal opinion of course).

But the other things? Oh, yeah. I've worked with (or attempted to) people like that, and I won't do it again. The first time a technical difference of opinion turns into a suicide threat, I'll just clean out my desk on my way out.