Twitter COO Ali Rowghani Is Leaving the Company

Twitter Chief Operating Officer Ali Rowghani is leaving the company, he said in a tweet Thursday morning.

The four-year Twitter veteran was rumored to be facing a change in duties, but the departure of an exec who the Wall Street Journal dubbed “Mr. Fix-It” as recently as April still came as a surprise to many.

Twitter, which hasn’t given a reason for Rowghani’s departure, told the Associated Press that Rowghani will stay on as a strategic advisor to CEO Dick Costolo. The firm also said it won’t name a replacement.

Rowghani joined Twitter as CFO in 2010 after leaving animation studio Pixar. He became Twitter’s COO in late 2012, before Twitter’s high-profile IPO last year. But the company has come under increasing pressure from investors to grow its number of users more quickly under Rowghani and Costolo.

The company’s stock price was up more than 1 percent at 9:45 a.m.