Jeff Dean, co-founder of leading AI research lab Google Brain, will now be in charge of Google's AI team.
In his new role, Giannandrea will report directly to Tim Cook as Apple looks to regain some of the relevance Siri once had.
According to Venture Beat, Giannandrea's role at Apple will include spearheading AI-focused products like Core ML for iOS app developers and Apple Neural Engine, which is a key component of the company's under-development AI-centric A11 processors for future iPhones.
"Our technology must be infused with the values we all hold dear", Cook was quoted as saying. At the time, he said that more efforts are required to make computers smarter so that they can think better.
Thousands of Google employees have signed on to a letter demanding that the company withdraw from its work on a Pentagon project that builds machine learning technology that could be used for drone warfare.
At Google, Mr. Giannandrea helped lead the push to integrate AI throughout Google products including internet search, Gmail and the Google Assistant.
Giannandrea will be tasked with improving Siri, the iPhone's digital assistant that seems to have grown less popular as competitors create proprietary devices that parallel, if not more.
While Apple has all the tools in place to take on Google Assistant, the implementation isn't quite there yet. In terms of quality, Apple Siri is way behind Google Assistant, which uses the same ground-breaking algorithms that power Google Translate and Google search image.
When news broke of Giannandrea's resignation from a very high-profile job at the world's top online search company, the reasons behind the decision weren't immediately clear. The hire is being flagged as a major victory for Apple, which has always been viewed as lagging behind its rivals Google, Facebook and Amazon when it comes to AI. Snagging Giannandrea is Apple's bid to improve AI quality and move its development forward.
Interestingly, Apple's less than impressive progress in AI can be considered to be the result of its own data collection and privacy policies.