“Tell me about some of the most difficult problems you worked on and how you solved them.”

Elon Musk

The Little Details

Musk described this at the 2017 World Government Summit in Dubai as the back half of the question he puts to every candidate. The front half is “tell me the story of your life and the decisions that you made along the way and why you made them”; the hard-problems half is where he says the real signal lives. Someone who genuinely solved a problem will “know exactly how they solved it,” down to “the little details.” Someone who only claimed the credit “can maybe go one level and then they get stuck.”

Someone who actually wrestled a hard problem to the ground carries the texture of it: the approach they tried first and why it fell apart, the constraint that forced an inelegant fix, the moment something finally clicked. You don’t even need to know their field to run the test. Keep following the thread, why that, how come, what then, and it either keeps going or it gives out, because real work holds far more detail than anyone can invent on the spot.