• Agrawal's appointment was announced internally in October.
  • Twitter's COO Anthony Noto announced his plan to leave in January to become CEO of SoFi in January.

Twitter on Thursday updated its website to reflect that it has appointed a new chief technology officer, Parag Agrawal. He takes the position most recently held by Adam Messinger, who left in late 2016.

The appointment was announced internally in October, during a quarter when Twitter managed to produce a net profit for the first time. Meanwhile, Agrawal came to the top rungs of Twitter's corporate leadership just before the company's operating chief, Anthony Noto, announced that he would leave.

Agrawal joined Twitter in October 2011 -- months after cofounder and current CEO Jack Dorsey returned to the company -- as an ads engineer, and he most recently held the title of distinguished software engineer. Before joining Twitter, he did research internships at AT&T, Microsoft and Yahoo. At Twitter his contributions include leading efforts to increase the relevance of tweets in Twitter users' timelines using artificial intelligence. But AI also comes in handy for things Twitter does behind the scenes, like preventing abuse on the social network.

"In his capacity as CTO, he's focused on scaling a cohesive machine learning and AI approach across our consumer and revenue product and infrastructure teams," a Twitter spokesman told CNBC.

Facebook, Google, Microsoft and other technology companies also use AI to enhance various parts of consumer services, as well as internal tools.

This isn't the first time Twitter went some time without a CTO. Its first CTO, Greg Pass, arrived in 2008 after Twitter bought Summize and left in May 2011. Messinger, a former Oracle executive, joined Twitter in November 2011 but only took over as CTO in March 2013.

Twitter stock is up 45 percent since the beginning of the year.