Kate Conger Ryan Mac and Mike Isaac

The social media platform now has a work force of less than 2,000, down from 7,500 when Elon Musk took it over in October.

Elon Musk has reduced the company to a bare-bones operation, and employees are under a “zero-based budgeting” mandate to justify any spending.

Mr. Musk, who is rapidly transforming the social media company, also has cut its contractor work force.

The layoffs hit across many divisions, including the engineering and machine learning units, the teams that manage content moderation, and the sales and advertising departments.