As of today, about 7,500 people work on Twitter. The Washington Post reports that 75% of them can be fired. Elon Musk, who is buying the company, has told potential investors that he plans radical layoffs to cut costs.

Musk must complete the operation of buying Twitter by October 28. Due to the fact that the deal is still not closed, Twitter has frozen the payment of bonuses to its employees for the time being. However, anonymous sources say the deal is moving forward as planned.

Job cuts were planned even before that. Even before Musk’s proposal, Twitter’s management had intended to cut nearly a quarter of its workforce, cutting $800 million from its payroll. Musk’s planned cuts are more massive and “unthinkable,” says Twitter’s former head of spam and health metrics. Users may notice these changes immediately, as Twitter is likely to experience more hacking attacks. Musk plans to implement stack ranking, a practice that ended at Microsoft in 2013 because it contributed to the deterioration of the company’s work culture.

Stack ranking is a process in which the management of each business unit must analyze the performance of employees and classify a certain percentage of them as top, average, or poor performers. Former Microsoft employees claimed that this led to competition among colleagues, especially when some employees in the group had to receive poor grades regardless of the circumstances, just to comply with the method.

Musk has also already told investors that he plans to double Twitter’s revenue in three years, but did not explain how that would happen.