• Elon Musk's xAI is known for its intense work culture. Founding member Toby Pohlen shared a peek inside.
• Pohlen described "a day and a half of straight coding and shipping" before Grok's 2023 release.
• After leaving xAI in February, Pohlen wrote that he was excited to get more than 8 hours of sleep.

Elon Musk's companies are "hardcore." It's even in his text messages.

When xAI founding member Toby Pohlen left the company in February, he shared a list of things he was excited for. He said he wanted to write down everything he learned, figure out what's next — and sleep over 8 hours.

On Wednesday, Pohlen offered another peek into the company's internal grind on X. He framed it as a "lesson" about learning how to work at an "extreme pace" and why it matters.

Pohlen went back to 2023, when xAI released the first version of Grok, its large language model. At 1:30 a.m. on November 3, Musk texted the xAI group chat that they would need to go "extremely hardcore" for 36 hours, Pohlen wrote.

"What unfolded over the next day and a half was one of the best examples of engineering at pace that I've ever seen," he wrote.

At the time, xAI only had a "somewhat fine-tuned base model and a half-baked UI," Pohlen wrote. They split up tasks and got to work, he said. By the following evening, the company announced Grok to the world.

Over two days, the xAI team took the company from "silence to relevance," he wrote.

"A day and a half of straight coding and shipping; no drugs, not even caffeine, just pure adrenaline," Pohlen wrote. "Elon gave us a mission and we delivered."

XAI's hardcore culture is well known among the industry. Memes about xAI employees sleeping in tents at the office abound on X. Employees describe 36-hour shifts and speed bets wagering a free Cybertruck.

For Pohlen, there's a lesson to be learned: Companies should "grind with purpose."

"When the goal and the means of reaching it are crystal clear, a small, skilled, and highly motivated team can outcompete companies old and new, big and small," he wrote.

Some critics have accused Silicon Valley's 996-ers of peacocking their hard work. Pohlen advises against this. "Never grind to show off; never work late to be seen; never sacrifice without cause," he wrote.

"A hardcore engineering culture is one of the most effective ways of accelerating real progress," Pohlen wrote. "Watch out for performative sacrifice and don't confuse pain with progress."