John Carmack has resigned as Meta's executive consultant for VR and left the company after almost a decade.

In a lengthy resignation email, posted in full by Carmack on Facebook after snippets were initially leaked to the press, the veteran programmer said the move signals the end of "my decade in VR" and noted he has "mixed feelings" about leaving the company.

Carmack spent years working at Meta as CTO of VR company Oculus after it was purchased by the social media turned metaverse platform (then known as Facebook) in 2013.

In 2019, Carmack stepped down as Oculus CTO to explore the world of artificial intelligence, but said he would remain at Oculus (which now operates under the Reality Labs moniker) in a consulting CTO position.

Now, three years later, Carmack has completely severed ties with Meta after becoming frustrated at inefficiencies within the company.

"This is the end of my decade in VR. I have mixed feelings. Quest 2 is almost exactly what I wanted to see from the beginning–mobile hardware, inside out tracking, optional PC streaming, 4k (ish) screen, cost effective," he wrote.

"Despite all the complaints I have about our software, millions of people are still getting value out of it. We have a good product. It is successful, and successful products make the world a better place. It all could have happened a bit faster and been going better if different decisions had been made, but we built something pretty close to The Right Thing.

"The issue is our efficiency. Some will ask why I care how the progress is happening, as long as it is happening? If I am trying to sway others, I would say that an org that has only known inefficiency is ill prepared for the inevitable competition and/or belt tightening, but really, it is the more personal pain of seeing a 5 percent GPU utilization number in production. I am offended by it."

Elaborating further, Carmack said that as a systems optimized person he cares deeply about efficiency, and that when you "work hard at optimization for most of your life, seeing something that is grossly inefficient hurts your soul"—suggesting that Meta's current performance level reminded him of seeing a "tragically low number on a profiling tool."

Carmack added that Meta has a "ridiculous amount of people and resources," but constantly squanders the tools and teams at its disposal through acts of "self-sabotage."

"There is no way to sugar coat this; I think our organization is operating at half the effectiveness that would make me happy. Some may scoff and contend we are doing just fine, but others will laugh and say 'Half? Ha! I’m at quarter efficiency!' It has been a struggle for me. I have a voice at the highest levels here, so it feels like I should be able to move things, but I’m evidently not persuasive enough," he continued.

"A good fraction of the things I complain about eventually turn my way after a year or two passes and evidence piles up, but I have never been able to kill stupid things before they cause damage, or set a direction and have a team actually stick to it. I think my influence at the margins has been positive, but it has never been a prime mover."

Carmack claimed his frustrations are partially "self-inflicted" because he chose to stick with the company after the Oculus acquisition, but suggested he would hardly have thrived had he moved to Menlo Park (Meta HQ) and "tried to wage battles with generations of leadership."

Looking ahead, Carmack implored Meta to fill its products with "Give a Damn" and work to improve its practices, but explained he'll now be focused on building artificial general intelligence at his startup Keen Technologies.