By Katie Paul and Sheila Dang

Oct 5 (Reuters) - Some Twitter employees were engaged in a company-wide planning process for next year on Tuesday when their phones began buzzing with news that Elon Musk had again reversed course in his on-again, off-again $44 billion bid to buy the company.

This time, the deal was on. The plans they were in the middle of presenting? Perhaps not.

One employee described a brief pause in a meeting to note the news, then continuing with discussions.

"I think everyone is used to the drama," said the person. "We're just along for the ride."

Months of whiplash over the deal have left employees used to uncertainty, and many greeted the news of Musk's proposal to return to his original offer with a sense of deja vu, three company sources who were not authorized to speak publicly told Reuters.

Since the world's richest person disclosed in April that he had acquired a stake in the social media platform, Musk has accepted and rejected a seat on Twitter's board, launched a bid to take the company private and tried to back out of the deal altogether.

The social media company is only pursuing about half the projects it normally would due to uncertainty about how many employees will flee, and to ensure it can deliver on commitments, one employee told Reuters.

Many blew off steam on the platform they run, tweeting about their confusion and perceived futility about planning for the future when Musk is expected to call for seismic shifts in how Twitter works.

"All of the frazzled nerves, all of the uncertainty, all of the worrying, all of the back and forth and back and forth, people I care about struggling and anxious," tweeted JP Doherty, an engineering manager at Twitter.

"And we just come right back to where it started, maybe. Unbelievable."

Multiple staffers tweeted a meme showing a paper labeled "2023 Planning," with a cartoon character first exclaiming "woah" and then saying "this is worthless."

Another meme popular with Twitter employees showed characters from the cartoon show SpongeBob SquarePants, with one labeled Elon and the other labeled Jack, for Twitter's founder and former CEO Jack Dorsey, who publicly backed Musk's bid.

The two stood smiling as buildings burned around them. "We did it Elon! We saved Twitter," the caption said.

Some employees in Twitter's internal Slack channel lamented they had sold some Twitter shares the day prior, before Musk's return to the deal prompted the stock to surge more than 22%, according to a source.