> So maybe the person shares actual code and walks us through it that they wrote, even if not open source? Again, we can't know for certain it is their own code and not some friend who wrote it for them 2 years ago that they claim is their own. Or was a teammate's, or what-have-you. So we can't count on that either.

Then you're not doing a very good walkthrough. I can generally spot someone who didn't write the code they are presenting almost immediately. Occasionally, someone might fool you, but it's pretty rare.

As one of my interviewers said many moons ago: "Yes, his claims and credentials sound overblown. But after reviewing his stuff and interviewing him, he either is exactly what he claims, or he's the best damn liar I've ever seen. Either way we should hire him--the only question is whether for engineering or marketing." :)