But everyone can do a whiteboard interview!
After a couple of these fiascos, I just gave up, and decided to start my own gig. I'm fairly good at what I do, and it really is too bad that it doesn't show in half-hour theory tests.
I do have a pretty massive portfolio, though. Comes from doing open-source software for over twenty years. I was paid to manage; not develop, so I needed to keep my tech chops up in other projects.
I also realize that this is not a typical thing. It's just my journey.
I thought it was funny that I mentioned this once, and someone insisted that I could have faked the portfolio.
If someone can fake ten years' worth of commit history, in dozens of repos, and tens of thousands of lines of code, as well as hundreds of pages of documentation, and dozens of articles, you should hire them immediately, because they are a genius.
Maybe I won't become a specifically-software person.
Then I read "Soul of a New Machine" by Tracy Kidder, a book that documents the design process of a minicomputer in the late '70s. The idolized manager of that project wants to hire young engineers fresh out of school so that he can mold them according to his wishes and have them working all-nighters. If that's your hiring principle, you're not going to get anyone with portfolios.
So I suspect it's an industry sickness that's been turned into a virtue over time.