As venture investors shift their focus from marketplaces and mobile apps to more complex fare, like AI and rockets, vetting start-ups can prove more challenging.

That's why they call Paul Willard, a former Boeing engineer and entrepreneur known as the "airplane whisperer" of Silicon Valley.

A newly minted partner at Storm Ventures, Willard has helped design airplanes and neural networks since the early 1990s. At Boeing he worked on Dark Star, an auto-piloted robotic spy plane that took pictures -- the plane's existence is now declassified.

"Some very bright engineers at Boeing in the early 90s decided to try to use a deep layered neural net to accurately predict drag on airplanes," Willard told CNBC. "I'm glad that I got that kind of exposure to 'AI' way back when. It's been instructive to everything I've done since."

But he's also no stranger to start-ups. He began to work for software companies, usually in senior product and marketing roles, back in the dotcom era. At one point he was director of product management at NextCard, one of the first online issuers of credit cards. Most recently, he was the chief marketing officer for Atlassian, which makes software for employees to collaborate more easily.

In 2013, when investors' interest in drones and space-tech was heating up, Willard began hearing from a number of Silicon Valley firms. Since then, he's advised at least a dozen funds, helping partners who don't have the same technical background to "due diligence" start-ups who promise to build a better aircraft, robot or satellite, for example.