BillÃÂ Stasior (William F. Stasior Jr.) is an American computer scientist and technology executive. He best known for leading Apple's virtual-assistant group, Siri, from 2012 to 2019 and for subsequent senior artificial-intelligence roles at Microsoft. Prior to joining Apple, he co-founded and ran Amazon's search-technology subsidiary A9.com, serving on Jeff Bezos's senior "S-Team".
Stasior earned his B.S., M.S. and Ph.D. in Electrical Engineering and Computer Science at the Massachusetts Institute of Technology (MIT). His doctoral research focused on interactive video processing and software-radio systems, with several technical reports published through MIT's Laboratory for Computer Science.
After graduate school, Stasior joined Oracle as a senior engineer and later became Director of Advanced Development at AltaVista, where he worked on large-scale web-search and contextual-advertising platforms.
Stasior joined Amazon in 2003 as Director of Search & Navigation and co-founded A9.com in 2004; he became its president and CEO in 2006. At A9 he oversaw product-search ranking, search advertising, and acquisitions such as the image-recognition start-up SnapTell in 2009. A 2009 Puget Sound Business Journal profile noted that A9 handled billions of product-search queries daily across Amazon's e-commerce sites.
Apple recruited Stasior in October 2012 as Vice President, Siri & Search, to rebuild the assistant's natural-language and machine-learning teams. Under his leadership Siri expanded to more than 30 languages and shipped across iPhone, iPad, Watch, Mac and HomePod. He stepped down amid a broader AI re-organization in early 2019 and departed Apple that May.
Microsoft announced in August 2019 that Stasior would join as Corporate Vice President of Technology, reporting to chief technology officer Kevin Scott and focusing on company-wide AI strategy.
In 2019, Stasior was appointed to the executive advisory committee at Avellino Labs.
In 2024, he was made a senior advisor at the Ontario Teachers' Pension Plan.
Stasior is listed as inventor on more than 50 U.S. patents spanning search ranking, vision-based commerce and conversational interfaces. He co-authored early peer-reviewed papers on multimedia systems while at MIT.
Technology media describe Stasior as a "search guru" and "prominent technologist" for his contributions to commercial search and voice AI.
According to public filings and professional profiles, Stasior resides in the San Francisco Bay Area and mentors early-stage technology founders.