Appropriately announcing his decision via a tweet from his personal Twitter (News - Alert) account, the company's Cheif Operating Officer (COO) Ali Rowghani has stepped down from his position at the social communications giant. “Goodbye Twitter,” the tweet reads in the short, sweet and to-the-point nature encouraged by the 140 character limit. “It's been an amazing ride, and I will cherish the memories.” Despite the fact that he will leave the company shortly, he will reportedly still serve as a “strategic advisor” to Twitter CEO Dick Costolo (News - Alert).

Suprisingly enough, Twitter also has no plans to hire any replacement for Rowghani's position as COO. Instead, the company will be assigning his former operating responsibilities to other members of the Twitter team, including Costolo who wants to take a more hands-on approach to company management. Sources close to the Twitter team report that the media and international unit responsibilities will likely be shifted to marketing and communications, while business development will be tackled by the sales division of the company.

Rowghani was reportedly under a lot of heat internally from Twitter for being unable to innovate the product or spur growth, which could be why Costolo wants a bit more direct control over the company's direction. While he was originally one of Twitter's best assets and climbed up the ranks from CFO to COO in the four years he worked with the company, his lackluster ability to accelerate growth was heavily criticized. Costolo was ecstatic to achieve 200 million active Twitter users back in 2012, and expected the company to double that number by the end of 2013. Unfortunately, the first quarter of 2014 resulted in a total number of only 255 million active users, which raised doubts about his ability to innovate the company.