Weeks after Jacob Coxon’s resignation from Anthropic sent shockwaves through the artificial intelligence industry, another employee at Google DeepMind has quit. Taking to his personal blog and X profile, Robert O’Callahan expressed profound concerns about AI-related issues. He went on to slam leading companies’ pursuit of what they call ‘Artificial Superintelligence’ (ASI) as “inherently irresponsible,” noting that his own team at Google was developing chips to enhance AI while he believes the booming tech was already “progressing too fast.”
While he is still not fully convinced that the “chance of ASI doom is 100%,” he said that the risk being “real,” even if “uncertain,” is in itself “very alarming.”
Robert’s exit comes after 27-year-old Jacob Coxon said that people working in the AI field strongly believe it could end humanity by the end of the decade. His own former boss, aka Anthropic CEO and co-founder Dario Amodei, has repeatedly called for AI development to slow down, in addition to signing an open letter titled ‘Pacing the Frontier’ in July alongside over 1,300 employees of frontier AI companies.
Last month, Bilal Chughtai, also a Google DeepMind researcher, resigned from the firm, fearing that humanity might soon run out of time to avoid an artificial intelligence-driven doomsday scenario. Others who recently departed for similar safety concerns include Anthropic’s Joe Benton, Google DeepMind’s Josh Engels, Anthropic’s Mrinank Sharma and OpenAI’s Caitlin Kalinowski.
Why is the Google employee quitting?
Calling it a difficult decision, the former Google employee shared the resignation letter he sent to the team. O’Callahan noted that while “being paid handsomely to solve fun puzzles” had been a great perk, he didn’t think his team’s goal to “make AI much cheaper and low-latency” was good for people. He based his decision to leave the company on how it was “practically impossible” for him to move to a different Google project that wouldn’t be working towards accelerating AI.
At the same time, O’Callahan admitted that even though taking his own foot off that “accelerator” would ultimately have a very small impact since millions of people are anyway contributing to that goal, it still wasn’t “no impact.”
Addressing an obvious question, given the recent string of resignations in the AI world, the ex-Google worker said that he already had this “date in mind for a while” due to a long-planned backpacking trip with his friends. He wanted to leave the company before embarking on that adventure on Monday. Simultaneously, he stressed that it was a mere “coincidence” that his company exit had aligned with the recent developments, including an open letter signed by top executives demanding the frontier be “paced.”
“It’s nothing to do with the recent spate of viral resignations or ‘AI slowdown’ warnings,” he added in his detailed blog.
My blog post with more details: https://t.co/s4pOoNJeVC HN discussion here: https://t.co/83WxgQ7FqV— Robert O’Callahan (@rocallahan) September 25, 2026
What’s next for Robert O’Callahan?
The Google employee said that he didn’t directly work on AI capability, but on improving tools for hardware chip design.
As he sent the initial resignation letter to the team, he didn’t have a concrete idea about what he would do next. At the time, he plans to investigate how AIs debug code and how debugging tools could help.
“I definitely want my future work to be unambiguously pro-human,” he emphasised in the letter.
As a firm believer in a higher power, O’Callahan wrote in his blog that he knows “God has a plan that’s good for us.” While he doesn’t know what it is now, his faith in it helps him sleep despite the “AI chaos.”
“So, as long as the talent God gave me is valuable, I want to keep working. As I mentioned above, I plan to continue maintaining Pernosco and rr,” he wrote online. “Under the Pernosco umbrella, I plan to study how AI agents debug code and whether debugging tools that can make them more effective at that. I want to use AI agents to bring some of my hobby project ideas to life. I’m keen to reap the benefits of AI, but cautiously, in ways that benefit humans and keep my own mind sharp. As much as I can, I will continue practicing and advocating for that here in New Zealand.”
The New Zealand-based techie joined Google Research in 2022 to work on various projects mostly related to debugging, according to his profile on Conf.researchr.org conference management system. Robert graduated with a PhD in Computer Science from Carnegie Mellon University in 2001. He eventually worked at IBM Research on dynamic program analysis tools from 2001 to 2004.
Having previously also worked with Mozilla, he led the development of “rr”, a practical record-and-replay debugger supporting reverse execution, in his last few years at the company. Many evelopers inside and outside Mozilla use it to the present day. After leaving the compay a decade ago, he co-founded Pernosco, a startup working on cloud-based, omniscient debugging leveraging rr.
As highlighted in his blog, he remains attached to both Pernosco and rr today.
Disclaimer: This is an independent report created using publicly available records, sources and news reports where applicable. Although Google was not contacted before this article’s publication, this content was produced in accordance with FinancialExpress.com’s editorial guidelines.
