After firing much of Twitter's senior management team, Elon Musk now plans to cut up to 30% of staff in certain departments, beginning this weekend, sources told Axios.

Why it matters: Musk's breakneck pace shows his determination to reshape Twitter's organization but could also result in chaos inside the company.

Driving the news: Cuts are expected to be made ahead of November 1, when most employees' quarterly grants of stock options are scheduled to vest.

• Last week, Musk fired four of Twitter's top execs, including CEO Parag Agrawal, CFO Ned Segal, general counsel Sean Edgett and policy chief Vijaya Gadde.
• Reports suggest those executives were fired "for cause," which could allow Musk to avoid large payouts in cash and stock.

Details: The layoffs are slated to begin this weekend, and it will be "a bloodbath — like 15-30%+" in the product organization, one source said.

• Ross Gerber, an investor, told The New York Times that he was told by the head of Musk's family office to expect up to 50% layoffs.
• Inside Twitter, sources dispute that number. "You wouldn’t be able to operate the company down 50% HC (head count)," one source said. After the layoffs, the source noted, 10-15% of remaining employees could likely leave due to the workload.
• Director-level staff and above are being asked to make lists of which employees to let go or who should be saved in their departments, one source said.
• It's not clear, even to those senior staffers, if their jobs will remain after they choose who should get cut and who should stay.

Sweeping layoffs are expected across the company with differing levels of cuts for organizations or teams.

• "I think folks are bracing for a black Monday, but the question is where will the majority of the cuts be," one source said.
• Cuts are expected to be particularly brutal on the product side, with engineering managers and product managers getting severely trimmed, per one source. Marketing is another area that's seen internally as somewhat bloated and could be targeted for steeper cuts.
• Employees ties to revenue could be spared. While Musk plans to add more subscription revenue to Twitter's top line, he does recognize the value of commercial partners, which is why he made an overture to advertisers last week. U.S. sales account for more than half of all revenue at Twitter.

The mood inside Twitter is a combination of exhaustion, anger and helplessness.

• "Most people seem to think they lack empathy," one Twitter employee said of the cuts.
• One point of frustration is the public excitement coming from Elon Musk's inner circle even as layoffs loom. One employee pointed to a tweet from Musk ally who Jason Calacanis, who tweeted Saturday, "Day Zero LFG! ☕️ 🐦."
• Outside of the engineering department, where Musk and his team seem to have spent the most time evaluating talent, employees feel mostly in the dark.

"Zero email. Zero slack. Zero internal comms from any of the new regime," one source said. They're still learning about what's happening on Twitter or through news reports.

• Twitter's communications team didn't respond to a request for comment.

Be smart: Sources say Musk and his team have a pretty good understanding of why they’re cutting certain organizations, teams, and leaders — at least on the product side — because they have been meeting with senior product leaders and observing the work of engineers for the past few weeks.

• "He’s def serious," one source said, noting how many director-level executives and above were shown as active on Slack all weekend. Others, they said, were in meetings or in the office on Saturday.

Between the lines: Twitter employees have been coping in their own creative ways, with dozens tweeting cheeky gif responses to news reports about the layoffs.

• "This is not an Oprah show, it's my life," one gif posted by an art director read.
• A product designer tweeted a picture of a dog sitting in a room up in flames saying, "This is fine."

What to watch: Musk has yet to announce who from his inner circle he will bring in to replace fired senior execs.