Twitter has appointed Parag Agrawal as its chief technology officer. Agrawal succeeds Adam Messinger. Messinger had left the organisation in late 2016. Agrawal had joined Twitter in 2011 as an Ads Engineer and has since then led efforts on scaling Ads systems, as well as creating and deploying a platform for online machine learning. Prior to joining Twitter, he did research in large-scale data management with collaborators at Microsoft Research, Yahoo! Research, and AT&T Labs. Agrawal had taken over the role of CTO in October last year, following an announcement made internally at that time.