Twitter employees showered internal Slack channels with farewell messages and salute emojis as Elon Musk's "hardcore" stay-or-go deadline passed on Thursday.

Earlier this week, Musk sent a late-night email to Twitter employees telling them to commit to his "extremely hardcore" vision for the firm or be laid off with three months' severance. The email contained a button for staff to click if they agreed with his vision and wanted to stay at the company, with a deadline of 5 p.m. ET Thursday.

"I'm not pressing the button," one departing Twitter staffer said in a Slack message Thursday, seen by The Verge. "My watch ends with Twitter 1.0. I do not wish to be part of Twitter 2.0."

Twitter's largest Slack channel, "social watercooler," was overwhelmed with salute emojis — company shorthand for saying goodbye to coworkers — Insider's Kali Hays reported.

In another Slack message, seen by The New York Times, one employee said: "I've met so many friends here. And will always remember the good times at twtr."

After the deadline passed, fewer than half of Twitter's remaining staff had committed to Musk's "hardcore" vision for "Twitter 2.0," Insider reported — leaving senior leadership grappling to convince some essential employees to stay.

"I have worked here at Twitter for over 11 years," one employee said in a Slack message seen by The Verge. "Back in July, I was the 27th most tenured employee at the company. Now I'm the 15th."