Twitter sees 'mass exodus' of employees ahead of Elon Musk's 'extremely hardcore' work deadline

"And just like that, after 12 years, I have left Twitter," tweeted Satanjeev Banerjee, Anadolu Agency (AA) reported.

After the deadline hit, what one employee called a "mass exodus" began, with hundreds of workers posting farewell messages and salute emojis on the Slack instant messaging platform announcing they had said "no" to Musk's ultimatum.

"I'm not pressing the button," one departing employee posted, according to The Verge technology news website. "My watch ends with Twitter 1.0. I do not wish to be part of Twitter 2.0."

Musk purged Twitter's 7,500-person staff by nearly half just two weeks ago after taking over the company in a US$44 billion buyout, with many more employees resigning shortly thereafter.

Twitter had about 2,900 workers remaining before Musk sent out an e-mail Wednesday demanding an overhauled work ethic for those wanting to stay with the platform, similar to the billionaire's expectations at his other companies, Tesla and SpaceX.

"Going forward, to build a breakthrough Twitter 2.0 and succeed in an increasingly competitive world, we will need to be extremely hardcore," Musk wrote. "This will mean working long hours at high intensity. Only exceptional performance will constitute a passing grade."

Employees who decided to leave Twitter have been told they will receive a severance package of at least three months' pay.

Twitter has already started recruiting outside engineers to see if they want to join "Twitter 2.0 - an Elon company," according to The Verge.