A longtime Android security leader is walking away from Google, saying the company he joined nearly a decade ago no longer reflects the values that once made it special.
René Mayrhofer, a senior leader in Android platform security, has resigned from Google after criticizing the company’s growing ties to the US military and what he described as a retreat from earlier environmental and ethical commitments.
In a farewell note to colleagues, Mayrhofer said his decision was driven by concerns over Google's direction under current leadership. Mayrhofer joined Google in 2017 as Director of Android Platform Security before later moving into a principal engineering and architecture role focused on Android security.
The resignation letter, which was later published on his personal website, has drawn attention across the technology industry because of its direct criticism of Google's leadership and AI strategy.
Why he joined Google
In the letter, Mayrhofer described Google as a very different company when he accepted the job offer nearly nine years ago.
He wrote that Android was one of the most exciting technology projects in the world and that Google fostered open debate, transparency, and employee participation in major decisions.
He also pointed to Google's past willingness to respond to employee concerns, including the cancellation of Pentagon-related contracts in response to internal opposition. He cited the company's 2018 AI principles, which stated that Google would not pursue certain military and surveillance-related applications of AI.
According to Mayrhofer, those commitments helped make Google attractive to engineers and researchers who wanted to build technology aligned with public interest and human rights.
Pentagon AI agreement sparks concern
A major turning point, Mayrhofer said, came after Google announced an agreement with the US Department of Defense in April that allows the military to use Google's AI technology for classified work.
The arrangement can include tasks such as military planning and intelligence operations. Mayrhofer argued that the deal conflicts with his personal beliefs.
“I am a pacifist, and have long ago decided that I will not personally work for militaries engaging in offensive warfare (strictly defensive action is somewhat different),” he wrote in a blog post titled Why I’m Forced to Say Farewell: Google Management Has Lost Its Moral Compass.
He added: “Proactively harming people is not something that I can or will be involved with.”
Beyond the Pentagon agreement, Mayrhofer accused Google's leadership of abandoning values that once defined the company.
“Google management has quietly abandoned its goals to become carbon-neutral because of the AI model energy usage,” he wrote. He also criticized what he sees as a lack of transparency surrounding major corporate decisions.
“None of this is being debated or communicated within the company,” Mayrhofer wrote. “It is just decided by top-level management.”
The criticism echoes concerns raised by some Google employees who have questioned the company's increasing involvement in defense-related AI projects. Earlier this year, Google DeepMind researcher Andreas Kirsch publicly criticized the Pentagon arrangement, saying he was “ashamed” of the decision.
What's next
Although Mayrhofer has resigned, he will remain at Google through Aug. 31, 2026, while serving his notice period and helping with the transition of ongoing projects.
He said he will immediately step away from any work connected to AI systems that could fall under the Defense Department agreement.
After leaving Google, Mayrhofer plans to continue research and development work focused on privacy, encryption, digital identity, operating system security, supply-chain security, and secure communications technologies.
Related reading: The controversy also arrives as Google navigates growing pressure around its AI strategy, including a recent crackdown on AI-generated search spam and misinformation in Australia and across APAC.