After Twitter closed all of its offices until Monday, Elon Musk suddenly summoned the remaining engineering staff to gather at Twitter's headquarters in San Francisco, United States. The meeting turned out to be just finished at midnight, what's wrong?

Last Thursday, after hundreds of its employees resigned in congregation, Twitter announced that it would close its office and temporarily turn off badge access from Friday (18/11) to Monday (21/11).

Shortly after, Musk sent out an email to all employees and asked the engineers who designed the software to gather at Twitter headquarters on Friday afternoon.

He asked the summoned Twitter employees to gather on the 10th floor, which has been where Musk has worked since he took over Twitter on Oct. 27.

Engineers on call are also asked to submit a 'bullet point summary' of lines of code they have written in the last six months, with up to 10 screenshots of the most prominent lines of code.

After the first call for Twitter engineers to come to the office, Musk also sent out a follow-up email inviting other employees to fly to San Francisco so they could be present in person at headquarters.

In one of his emails, the world's richest man said he would be working late at Twitter headquarters on Friday and Saturday mornings.

Early Saturday morning, around 1:30 a.m. western United States time, Musk posted a tweet on Twitter saying he had just left the Twitter office after completing a code review with engineers, as quoted by Business Insider, Sunday (20/11/2022).

In that tweet, Musk also uploaded a photo of himself with a group of Twitter engineers, as well as a whiteboard containing the results of discussions about the Twitter application and web. It is not known what the meaning of the graffiti is, but in the middle it says 'Timeline Mixer' which is divided into 'People Discovery Service', 'Ad Mixer' and 'Onboarding Service'.

Responding to a user's tweet that said the Twitter office looked livelier in the early hours of the morning than during the day, Musk said it was the largest number of people he had ever seen in a Twitter office building.

Musk's order to gather engineers at Twitter headquarters was issued a day after the mass resignation that rejected his ultimatum. Musk asked the remaining Twitter employees to choose between following a more hardcore job or resigning.

The New York Times and Fortune reported that around 1,200 Twitter employees resigned after Musk's ultimatum. Some divisions at Twitter are not even staffed at all