Cognizant has roped in former Mphasis CEO Ganesh Ayyar to head the company’s digital operations. He will replace Sumithra Gomatam, who has resigned.

Gomatam was the fourth high profile executive at Cognizant to resign in the last three months. Prasad Chintamaneni, Cognizant’s President for Industries & Consulting vertical, resigned in May; Debashis Chatterjee, EVP and president of global delivery, and Rajeev Mehta, President at the corporate level, resigned in April.

Ayyar, who was with Mphasis from January 2009 to January 2017, took the company past $1 billion in revenue. During his period, private equity player Blackstone India bought Mphasis for ₹7,100 crore (in April 2016), making it one of the largest deals in India.

At Cognizant, Ayyar, as Executive Vice-President and Head of Digital Operations, will lead a team of over 65,000 associates and serve nearly 150 strategic clients.

“After an extraordinary 24-year career with our company, Sumithra Gomatam, our EVP and President of Digital Operations and a member of the Executive Committee, has let me know of her plans to retire from Cognizant,” Cognizant CEO, Brian Humphries, announced in an e-mail communication to employees.

Gomatam was driving strategy, market share, and mind share while growing businesses across IT and BPO services.

Resignations of senior officials, who have been with the company for over two decades, were only expected as there is a major overhaul at the top level after Humphries took over as the new CEO earlier this year, said a source in Cognizant.