Lars Rasmussen has quit Facebook after nearly five years as director of engineering at the free content ad network.
He defected from Google to the Mark Zuckerberg-run company in 2010 in the immediate aftermath of the failure of his wonky Wave project, which he described at the time as being a "little stressful" to try to get off the ground at the Chocolate Factory.
Ad giant Google, he had claimed, lacked the patience apparently needed for Wave to grow, so off he popped to Facebook.
During his time at Zuck's siloed empire, Rasmussen oversaw development of the firm's Graph Search service and, more recently, its Facebook at Work project – a planned biz-chummy platform.
Facebook confirmed in a statement to The Register that Rasmussen had parted ways with the company to pursue a new venture:
We are grateful for Lars' many contributions over the years. We're a company of entrepreneurs and now that Facebook at Work is off the ground and growing quickly we understand Lars' desire to return to his startup roots.
Rasmussen, who built the original Google Maps alongside his brother Jens when they joined the multinational back in 2004, said:
"Leaving Facebook was an incredibly difficult decision! Working there has never been more exciting for me, in particular given the momentum behind Facebook at Work."
He added: "But over the past year my fiancé, Elomida, has built what I think is a new and exciting way to compose and experience music. And trying to turn that into a successful startup together will be way too much fun to postpone any longer."
According to TechCrunch, which was first to report on Rasmussen's departure, two London-based wonks will now run the firm's Facebook at Work project.
Apparently, this is necessary due to the scale at which the project has grown since its inception.
That said, Rasmussen has jumped ship before Facebook at Work is unveiled to world+dog. We surely shouldn't consider this a snub against Zuck, though, right? ®