Twitter laid off at least 200 of its employees on Saturday night, three people familiar with the matter said, or about 10 percent of the roughly 2,000 who were still working for the company. Elon Musk, who acquired the social media platform in October, has steadily pared back its work force from about 7,500 employees as he has sought to reduce costs.

The layoffs came after a week when the company made it difficult for Twitter employees to communicate with each other. The company’s internal messaging service, Slack, was taken offline, preventing employees from chatting with each other or looking up company data, five current and former employees told The New York Times. On Saturday night, some employees discovered that they were logged out of their corporate email accounts and laptops, three of the people said — the first hint that layoffs had begun.

By Sunday morning, the scope of the cuts was becoming clear. Some Twitter employees used the platform to post farewell messages, while workers who had kept their jobs scrambled to use encrypted messaging services like Signal to determine who else was left. By Saturday night, the remaining employees had also lost access to a Google chat service associated with their work email accounts, three people said.

The cuts hit product managers, data scientists and engineers who worked on machine learning and site reliability, which helps keep Twitter’s various features online. The monetization infrastructure team, which maintains the services through which Twitter makes money, was reduced to fewer than eight people from 30, a person familiar with the matter said.

Among those affected by the layoffs were several founders of small tech companies that Twitter had acquired over the years, including Esther Crawford, who co-founded a screen-sharing and video chat app called Squad and recently oversaw Twitter’s effort to charge users for verification check marks, and Haraldur Thorleifsson, the creator of the design studio Ueno, which Twitter purchased in 2021. Several of the founders received higher compensation packages as part of the acquisitions of their companies, which could make it more expensive to lay them off as their stock and bonuses are paid out, three people familiar with the compensation packages said.

Saturday’s round of layoffs was one of the largest since Mr. Musk told employees in an internal meeting in late November that there were no more plans for staff reductions. The cuts followed a mass layoff in early November, when Mr. Musk eliminated about half of Twitter’s work force a week into his ownership of the company. Smaller layoffs and resignations had since reduced Twitter’s staff to around 2,000 employees.