Character.AI co-founder and CEO Noam Shazeer left Google in October 2021 to found this a16z-backed startup. In previous work, Shazeer led the research team to build the language model LaMDA (Language Model for Dialogue Applications) used in conversational artificial intelligence tools.

Character.AI co-founder Daniel DeFreitas and several other employees from the company will also join Google. Dominic Perella, Character.AI’s general counsel, will become the startup’s interim CEO. The company noted that most employees will remain at Character.AI.

Google also signed a non-exclusive agreement with Character.AI to use its technology.

"I'm extremely excited to return to Google and be part of the Google DeepMind team. I'm extremely proud of everything we've done at Character.AI over the past three years. I believe the funding from Google's non-exclusive licensing agreement, coupled with the incredible Character.AI team, will position Character.AI for continued success in the future," Shazeer said in a statement.

Google said Shazer will join the DeepMind research team, but did not specify the specific responsibilities of him and de Freitas.

Google said in a statement: "We are especially pleased to welcome back Noam, a distinguished researcher in the field of machine learning, who will join a handful of his colleagues on the Google DeepMind research team. This agreement will provide additional funding for Character.AI to continue to grow and focus on building personalized artificial intelligence products for users around the world."

Character.AI has raised over $150 million in funding, primarily from a16z.

"When Noam and Daniel founded Character.AI, our goal of personalized superintelligence required a full-stack approach. We had to pre-train, post-train our models to deliver the experiences that set Character.AI apart, and build a product platform that could reach users around the world," Character.AI announced the move on its blog.

"However, over the past two years, things have changed; there are now more pre-trained models available. Given these changes, we see more advantages in leveraging third-party LLMs as well as our own. In this way, we can devote more resources to post-training and create new product experiences for our growing user base."

Various regulatory agencies in the United States and the European Union, such as the Federal Trade Commission (FTC) and the Department of Justice (DoJ), are likely to subject these reverse takeovers to strict scrutiny. Last month, the UK Competition and Markets Authority (CMA) announced that it was investigating Microsoft's hiring of key personnel from InflectionAI to understand whether the technology giant was trying to evade regulation. The U.S. Federal Trade Commission (FTC) also launched a similar investigation in June this year, investigating Microsoft's $650 million transaction.