Adding to the recent exodus of high-level executives at the troubled social media company, Twitter's  (TWTR)  chief technology officer, Adam Messinger, announced on Tuesday afternoon that he's leaving the company.

Messinger, who had been Twitter's CTO for four years, announced his departure, appropriately enough, in a tweet:

After 5 years I've decided to leave Twitter and take some time off. Grateful to @jack for the opportunity and to my team for shipping.

— Adam Messinger (@adam_messinger) December 20, 2016

Messinger didn't specify what he'll be doing now, but he added in an official statement that he is "confident that we have the right team, plan and leadership structure in place for Twitter to succeed."

Shares of the San Francisco-based company were sliding about 0.4% to $17.85 in after-hours trading after falling 1.8% during the day. The stock is down roughly 23% so far this year.

A Twitter spokesperson said that the company has been making progress to refine the company's core service which has led to a "direct positive impact on audience engagement and growth." That effort includes some organizational and reporting changes.

"To further accelerate this positive momentum, we're taking steps to streamline and flatten the organization by elevating our engineering, product and design functions, with each area now reporting directly to Jack," the company said in a statement. "We believe these updates to our organizational structure will enable increased discipline in our product strategy and faster execution."

Messinger's move comes on the heels of the departure of COO Adam Bain in November. Bain had been with the company since 2010 and had held the COO post since October 2015. Twitter's CFO Anthony Noto has taken Bain's spot and will remain as CFO until the company finds a replacement.

Twitter has also seen high turnover in its important product VP position. The company brought on Keith Coleman, former CEO of start-up company Yes, in December as the new product VP. Prior to Coleman, the job had been essentially vacant -- Kevin Weil was the last person to have the role full-time, but he left the company in January. Coleman is now the sixth product chief at the company since 2007.

Additionally, Twitter is in the midst of a restructuring effort that has led the company to trim 9% of its workforce to become more efficient. Twitter's CEO Jack Dorsey, who also helms payment company Square (SQ) , said that the company is focusing on improving its core service.

In the third quarter, Twitter saw a 3% year-over-year increase in monthly active users, down from 11% growth in the same quarter in 2015.

More from Stocks

Dow Trades Higher, Nasdaq Regains Footing as Chipmakers Fall

Dow Trades Higher, Nasdaq Regains Footing as Chipmakers Fall

Chip Stocks May Have Sold Off Too Much On Recent Spate of Bad News

Chip Stocks May Have Sold Off Too Much On Recent Spate of Bad News

Walmart Bulls Ring up Profits After Earnings Beat

Walmart Bulls Ring up Profits After Earnings Beat

Tesla Has Lost 15% Since Musk's Take-Private Tweet

Tesla Has Lost 15% Since Musk's Take-Private Tweet

Here's How to Trade Walmart, Nordstrom, Macy's and JCPenney After Earnings

Here's How to Trade Walmart, Nordstrom, Macy's and JCPenney After Earnings