This quick question can still expose North Korean spies in an instant
Crypto journalist Laura Shin published a brilliant report after exposing a North Korean spy in real-time during a job interview by presenting them with an impossible question:
"Can you say something negative about Kim Jong Un?" or any variation of a question that elicits a critical response about the North Korean leader is a fairly reliable way of weeding out North Korean spies during a video call. North Korea is such a restrictive regime that any citizen found criticizing the country's leader can face a swift forever offlining, if you catch my drift.
North Koreans showing up as remote employees are a growing problem for pretty much every business, including open source developers and the crypto industry, by using stolen and forged government-issued IDs, resumes, and other documents to gain employment. Once in, they earn a wage, funnel the money back to the regime, then steal data and extort the company for even more money. Identifying North Koreans before they are hired as employees can be a challenge. But some companies are increasingly relying on unusual interviewing techniques, like asking the same kinds of questions that Shin did.
Shin's report is worth the read, and shows that asking this question can still be highly effective. Consider this the first of many questions you should be asking during a job interview. North Koreans, even the ones who are allowed outside the watchful eyes of Pyongyang into neighboring China, Russia, and Laos, have their movements highly restricted. Asking them about their favorite things to do in the U.S. town that they claim to live in is one other way to trip up someone who has never really lived there.

