HN doesn't seem to like mine, but I've always asked "tell me about some project, can be a tiny shell script, that you did entirely by yourself: the code, the docs, the install". It has to fit through the filter of nobody asked you for help, if they sent you a thanks, that's cool, but they need to be able to install/learn/use it on their own.

If someone is claiming to be an architect and they've never done that, that's a red flag for me. Kinda like asking a building architect to talk about framing. You'd be surprised at how many of those guy have never swung a hammer and they "design" stuff that can't be built. Sort of the same with software, IMHO.