Musk, the world's richest person, is leading President Donald Trump's federal cost-cutting efforts under the so-called Department of Government Efficiency (DOGE).

The Treasury's closely guarded payments system handles the money flow of the US government, including $6 trillion annually for Social Security, Medicare, federal salaries, and other critical payments.

Ryan Mac, co-author of the recently released book "Character Limit: How Elon Musk Destroyed Twitter," told AFP what the tycoon's involvement could mean for massive federal agencies.

Q: What did Musk make of Twitter?

A: "Elon Musk saw Twitter as a bloated company that was being mismanaged. He fashioned himself as a great cost cutter.

"He has done this for years at Tesla and SpaceX. That is the same principle he applied after buying Twitter.

"Now, we are seeing the impacts of that. More than 80 percent of the company has departed, been laid off or fired.

"Costs have been severely reduced, in turn that's also reduced revenue - that side of the business has been hammered. He's taking those same tactics to the US government."

- Is Musk stripping funds?

"In the same way that Musk has zeroed out budgets at Twitter, he is doing the same with whatever federal agency he is taking an interest in.

"They take a contract or expenditure down to zero, then the employee overseeing it has to argue why it's necessary.

"They reassemble the budget based on that and, hopefully, have been able to find some efficiencies or things that could have been cut.

"That is something we saw at Twitter that's now being deployed in the federal government.

"We're seeing the same names of characters, people like Steve Davis who is Elon's right-hand man that came in to Twitter to slash costs. He's now part of the DOGE effort with the federal government."

Will engineers rule?

"We'll start to see a heavy reliance on engineers. Elon is driven by this idea that engineers should be the decision makers; everyone else should either help them build or get out of their way.

"That's why you're starting to see these young engineers coming to these agencies overseeing stuff.

"I also expect to see burnout and people that initially sign on to work with him at DOGE start to fall out along the way. That's a natural attrition you get with working with someone as intense as him. People no longer see eye-to-eye or get tired of the pace and leave or get fired."

Is Musk's rule illegal?

"Elon's view on laws are they are something that can be challenged. He has this way of thinking called 'going to first principles.' If you tell him he can't do something, he will ask why.

"I think you are starting to see a little shift in his strategy. The 'Fork in the Road' email is similar to an email he sent out at Twitter after his takeover. At Twitter Elon asked workers who wanted to stay for hard core devotion to their jobs.

"With the federal government, you have to opt in to resign. He has learned from his past mistake."

Did cuts break Twitter?

"There were some outages, and the crash on X when Ron DeSantis announced his run for president was quite embarrassing.

"X has remained online for the most part, and Elon sees that as a big win. We can talk about the cratering of revenue at X, but the site has been online, and he'll take that as a victory.

"But, the federal government is not something you can just slash willy nilly and put things back in place if it doesn't work. People will get hurt along the way. What happens when you slash Social Security or Medicare too far? Whatever federal payment gets cut off, reassembling that is not as simple as turning on a server again or rehiring the person you just fired.

"He has not built up these federal bureaucracies. Now he's coming in and trying to fly the airplane and change the engine in mid-flight."