Twitter chief technology officer Adam Messinger tweeted he will leave the company and "take some time off," one of two top staffers on Tuesday to join the exodus of staff from the social media company.
Josh McFarland, vice president of product at Twitter, will also leave the company early next year.
The moves come as the company is "streamlining" its organizational structure, with more teams, including engineering and design, reporting directly to co-founder and CEO Jack Dorsey.
"Thank you for everything you've done for Twitter Adam! I have learned so much from you, and appreciate everything you stand for," Dorsey tweeted.
Messinger has been working with Twitter for five years and became the CTO in March 2013. As chief technology officer, Messinger was responsible for engineering, product development, and design.
McFarland, at Twitter for nearly 2 years, will become a partner at top-tier Silicon Valley venture firm Greylock Partners. The company hired Keith Coleman, who rarely tweets, as vice president of product earlier this month.
Twitter's leadership ranks have been roiled by turnover, with product guru Dorsey back at the helm just over a year, while also juggling duties at Square.
Adam Bain stepped down as chief operating officer last month. The company replaced Bain with Anthony Noto, leaving Twitter in search of a chief financial officer. Twitter has also lost leaders from business development, media and commerce, media partnerships, human resources, and engineering this year.
Employee morale at Twitter has reportedly struggled this year, with some employees not showing up for work as of October,The New York Times reported. Twitter said in October it would lay off 9 percent of its employees and shut down video app Vine to keep its costs down.
As Twitter's advertising revenue and user growth have failed to keep pace with companies like Facebook, it has been widely speculated that the company might sell itself. Shares have fallen more than 22 percent in a rollercoaster trading year, as no clear buyers emerged for the social media property.
While Twitter is used with much influence by powerful people like president-elect Donald Trump, Twitter has looked to revive its product with live streaming events like presidential debates and NFL games.
Messinger said in a statement that he felt Twitter's new leadership structure provides the right plan for success.
"Throughout 2016, we've made progress refining our core service, launching live streaming video, giving people more control over their Twitter experience, and promoting and recruiting great talent," Twitter said in a statement.
— CNBC's Julia Boorstin and Reuters contributed to this report.