John Carmack is leaving Meta after more than eight years at the company, according to an internal post reviewed by The New York Times.

The technologist criticized his employer in the post. Meta, which is in the midst of transitioning from a social networking company to one focused on the metaverse, is operating at half the effectiveness and has a ridiculous amount of people and resources.

Mr. Carmack said in the post that it had been a struggle for him. I feel like I should be able to move things, but I'm not persuasive enough.

One of the most influential voices in the development of V.R. headsets was Mr. Carmack. He stayed with the company after they changed their name to Meta.

Even though Meta was moving quickly into an area that Mr. Carmack specialized in, he was sometimes a dissenter. He criticized the decision-making and direction set forth by Mr. Facebook and Andrew Bosworth, Meta's Chief Technology Officer. Mr. Carmack used to work for the company part time.

Mr. Carmack and Meta did not reply to questions.

Meta has been hit hard by its spending on the metaverse and its slow growth in social networking and digital advertising. The company's first sales decline as a public company took place in July. Meta said last month that it was laying off about 11,000 employees, or 13 percent of its work force.

Mr. Carmack said in the interview that he was sick to his stomach because of Meta's $10 billion loss at the time. He said that the company's metaverse efforts have been hampered by bureaucratic issues.

Mr. Carmack was not a fan of features on the company's headsets. He said in his farewell post that the Quest 2 headset was almost exactly what he wanted to see from the beginning in terms of its cost and hardware.

He said that they built something close to the movie.

Mr. Carmack said in his post that he would focus on his own start-up after 10 years in V.R. He said in August that his firm had raised $20 million.

No company is better positioned to bring value to most of the people in the world than Meta.

The techniques that Mr. Carmack pioneered in computer graphics became crucial to games that he developed. He moved into a part-time role after stepping down from his position as chief technology officer.

The Federal Trade Commission tried to block Meta's purchase of Within, a virtual reality start-up behind a fitness game. If the tech giant is allowed to complete the deal, it will eliminate competition in the metaverse. Next week is when the hearing is expected to go on.