Some of those who are being asked to return were laid off by mistake, according to two people familiar with the moves. Others were let go before management realized that their work and experience may be necessary to build the new features Musk envisions, the people said, asking not to be identified discussing private information.

Twitter cut close to 3,700 people this week via email as a way to trim costs following Musk’s acquisition, which closed in late October. Many employees learned they lost their job after their access to company-wide systems, like email and Slack, were suddenly suspended. The requests for employees to return demonstrate how rushed and chaotic the process was.

A Twitter spokesperson did not reply to a request for comment. Twitter’s plan to hire back workers was previously reported by Platformer.

“Regarding Twitter’s reduction in force, unfortunately there is no choice when the company is losing over $4M/day,” Musk tweeted on Friday.

Twitter has close to 3,700 employees remaining, according to people familiar with the matter. Musk is pushing those who remain at the company to move quickly in shipping new features, and in some cases, employees have even slept at the office to meet new deadlines.

Over the weekend, Twitter rolled out a new Twitter Blue subscription plan, offering a verification check mark for any user who pays $8 a month. The company also said it will soon be launching other features, including half the ads as well as the ability to post longer videos and to get priority ranking in replies, mentions, and searches.

The New York Times on Sunday reported Twitter will delay changes to the check marks until after Tuesday’s midterm elections, after users and employees raised concerns that the plan could be misused to sow discord.