The latest biography of Elon Musk, by technology journalist Ashlee Vance, provides an in-depth look into how the entrepreneur and tech titan built Tesla Motors and SpaceX from the ground up, often in the face of enormous personal and professional challenges. For those coders and developers who’ve always dreamed of participating in the space industry in some capacity, and want to work for SpaceX at some point, the biography offers some key insights into the rocket company’s hiring processes. For starters, given the highly specialized nature of the work, SpaceX is understandably rigorous when it comes to recruiting, often targeting engineers and researchers based on their published work; it also sends HR staff to trade shows and conferences to hunt for the best of the best. As with many other tech firms, SpaceX subjects its job candidates to a battery of rigorous quizzes and tests. “Companies will typically challenge software developers on the spot by asking them to solve problems that require a couple of dozen lines of code,” Vance writes at one point. “The standard SpaceX problem requires five hundred or more lines of code.” If that wasn’t challenging enough, SpaceX tries to separate those candidates who’re just looking for a job from those with a genuine passion for spaceflight by asking all of them to write an essay for Elon Musk “about why they want to work at SpaceX.” But the last step might prove the most challenging of all: an interview with Elon Musk himself. Despite SpaceX's rapid growth, Musk still manages to meet with key personnel before they come onboard. Often branded as mercurial and brilliant, he reportedly suffers no fools, and likes to pick every brain in the vicinity. “The tales of engineers who have interviewed with Musk run the gamut from torturous experiences to the sublime,” Vance writes. “He might ask one question or he might ask several.” During that interview, Musk likes asking candidates a particular brainteaser:

“You’re standing on the surface of the Earth. You walk one mile south, one mile west, and one mile north. You end up exactly where you started. Where are you?”

If you can answer that riddle successfully, and pass all of SpaceX’s other stringent tests, you may have a shot at launching rockets into orbit.