Desai is a highly-respected and experienced coach and has worked with several teams at the franchise level as well as with several international teams.
He joins the management which also includes bowling coach Roddy Estwick and fielding coach Rayon Griffith.
Simmons said he's looking forward to Desai helping the West Indian players improve on their talent and perform better.
Desai looks forward to working with the Windies team
"I am very much looking forward to being part of a journey where I can help to create a winning work environment, learn and embrace a new culture, and build a 'happy dressing room' tradition alongside other excellent leaders," Desai said in an official statement.
Desai has worked with Canada, Afghanistan, UAE and Nepal
Earlier, Desai served as Canada's head coach at the ICC World Cricket League Division 2.
He helped Afghanistan at the ICC World Cup qualification tournament in 2018.
Recently, Desai was the batting coach for the United Arab Emirates (UAE) at the ICC T20 World Cup qualification event.
He worked with Nepal during his stint as a batting coach in 2015 ICC World Twenty20 Qualifiers.
Desai's association with the Indian Premier League
Desai had earlier worked as a coach and head scout for Indian Premier League (IPL) team Rajasthan Royals from 2008 to 2015.
He had joined RR in between completion of first season and start of the second.
Meanwhile, after the suspension of the Royals, he worked as a performance coach for Gujarat Lions for next two seasons.
Other crucial stints of Desai in the past
Desai has also worked with former England coach Andy Flower during the side's tour of India in the past.
He also conducted a specialized camp for World Cricket Academy (WCA) to help County cricketers in enhancing their skills.
He had also coached USA's South East region.
Desai, who is a celebrated figure, was also the head coach of Andhra during the 2018-19 domestic season.