What's with the standard of doing a full day interview? Who does this work for other than fresh graduates? I don't want to spend a whole day (which I have to request off from my current employer) answering probably-silly technical puzzles as the first round interview (the 25 minute phone call doesn't really count since it sounds like just a pitch). Does a full day of whiteboarding really get you better candidates tha…
If you're a serious engineer that is demonstrating consideration: 1-2hr homework doesn't exist. Attention to detail, considering corner cases, test cases, documentation, and polishing takes time. I do agree with you the whole "let's stress him out till he fails one of the tests and then fail him" gauntlet is just annoying.
There's a contingent of very detail oriented people who believe they are introverts because they tire easily at this kind of persistent over-stimulation. These people will wash out of the process before the culture fit interview in the afternoon. All you've done is increased your odds of getting a bunch of coding cowboys.
The fact is that nobody in a real business situation should be put into this sort of pressure cooker situation on a regular basis. That you're selecting for this indicates a pretty gross failure of management to manage. And until people push back the problem won't get solved. Hiring more people that think that's okay? One way to look at it is that it's a public service you're doing for the rest of the industry by keeping people like that out of our hair. Except people do what they know and any junior folk will just think this is normal and okay. It's not okay and I wouldn't even say it's normal.
A pressure cooker interview tells me this place is high drama and they're looking for people with a high tolerance for bullshit. I want to get shit done and do it well (not perfect - well), and that's probably not happening at a place like this.