Dorsey’s exit shakes up Twitter future

Jack Dorsey’s announcement Monday that he is exiting Twitter after co-founding the company and serving as its CEO for the last six years is a seismic shift for a social media company at the heart of politics and the news media.

The eccentric CEO’s departure comes as Twitter has set high new goals for user and revenue growth and rolled out a series of new products.

It also takes place as Twitter remains under the microscope for the role it and other social media firms have played in stoking an increasingly divided nation.