Buzzy EV startup Rivian has lost its first chief technology officer just nine months after he started the job. Mike Bell, a longtime Apple executive who helped start the iPhone project, left Rivian this month, the company confirmed to The Verge.

Rivian hired Bell in June 2019, as The Verge first reported last year. He previously spent five years as an executive at Intel, where he ran the company’s mobile division, and three years at Palm, where he helped bring the Pre into the world. He also worked at Motorola before spending 15-plus years at Apple.

It’s unclear why Bell left Rivian after just nine months; he did not respond to a request for comment. He was just featured in the first episode of a documentary-style “behind the scenes” series on Rivian’s YouTube channel published on February 6th. In it, Bell explains that he was “very lucky to lead the groups that created Wi-Fi, the iMac,” and that he helped bring the original iPhone into the world. He describes, with a smile, that Rivian is a “BHAG” company, which stands for “big hairy audacious goal.”

Bell is one of Rivian’s most high-profile hires to date, though the startup has now grown to over 1,700 employees worldwide, as the company confirmed last month. Amy Mast, a spokesperson for Rivian, said the company “appreciate[s] his contribution here and wish[es] him all the best,” but declined to offer any more information about his departure.

Since he took the post last year, Bell helped bring a small stream of former co-workers to Rivian from Intel and Silver Spring Networks, a smart grid company that he ran from 2015 to 2018, according to a person familiar with the matter and public information from LinkedIn. A few of those former Intel co-workers joined Rivian from camera company RED, where they worked on the poorly reviewed and now-defunct Hydrogen One smartphone.

Founded in 2009, Rivian spent nearly a decade operating in stealth mode while developing two electric vehicles: a pickup truck and an SUV. The startup broke cover in 2018 and revealed the vehicles later that year at the LA Auto Show. Both of those vehicles are slated to hit the market at the end of this year, and will retail for around $70,000.

Rivian then went on a torrid hiring spree, as The Verge reported last year, scooping up talent from damaged EV startups like Faraday Future and established players like Ford, McLaren, and Tesla.

At the same time, the startup locked down an incredible amount of financing. Amazon led a funding round worth $700 million. Ford invested $500 million. Cox Automotive put $350 million into Rivian. And just last month, Rivian announced it raised another $1.3 billion in a new funding round led by T. Rowe Price that included existing investors like Ford and Amazon.

In return, the startup has agreed to help Ford build an all-electric Lincoln SUV powered by Rivian’s EV platform. Rivian will also help build 100,000 electric delivery vans for Amazon.