Academic research At Carnegie Mellon, Lee worked on topics in machine learning and pattern recognition. In 1986, he and Sanjoy Mahajan developed
Bill, a Bayesian learning-based system for playing the board game
Othello that won the US national tournament of computer players in 1989. In 1988, he completed his doctoral dissertation on
Sphinx, a large-vocabulary, speaker-independent, continuous speech recognition system that drew wide notice in the field. Lee has written two books on
speech recognition and more than 60 papers in computer science. His doctoral dissertation was published in 1988 as a Kluwer monograph,
Automatic Speech Recognition: The Development of the Sphinx Recognition System (). Together with
Alex Waibel, another Carnegie Mellon researcher, Lee edited
Readings in Speech Recognition (1990, ).
Apple, Silicon Graphics, and Microsoft After two years as a faculty member at Carnegie Mellon, Lee joined
Apple Computer in 1990 as a principal research scientist. While at Apple (1990–1996), he headed R&D groups responsible for
Apple Bandai Pippin,
PlainTalk, Casper (speech interface), and GalaTea (text to speech system) for Mac Computers. Lee moved to
Silicon Graphics in 1996 and spent a year as the Vice President of its Web Products division, and another year as president of its multimedia software division, Cosmo Software. In 1998, Lee moved to
Microsoft and went to
Beijing,
China where he played a key role in establishing the
Microsoft Research (MSR) division there. MSR China later became known as Microsoft Research Asia, regarded as one of the best computer science research labs in the world. Lee returned to the United States in 2000 and was promoted to corporate vice president of interactive services division at Microsoft from 2000 to 2005.
Move from Microsoft to Google In July 2005, Lee left Microsoft to take a position at
Google. The search company agreed to compensation worth in excess of $10 million, including a $2.5 million cash 'signing bonus' and another $1.5 million cash payment after one year, a package referred to internally at
Google as 'unprecedented'. On July 19, 2005, Microsoft sued Google and Lee in a
Washington state court over Google's hiring of its former Vice President of Interactive Services, claiming that Lee was violating his
non-compete agreement by working for Google within one year of leaving the Redmond-based software corporation. Microsoft argued that Lee would
inevitably disclose proprietary information to Google if he was allowed to work there. On July 28, 2005, Washington state Superior Court Judge Steven González granted Microsoft a temporary restraining order, which prohibited Lee from working on Google projects that compete with Microsoft pending a trial scheduled for January 9, 2006. On September 13, following a hearing, Judge González issued a ruling permitting Lee to work for Google, but barring him from starting work on some technical projects until the case went to trial in January 2006. Lee was still allowed to recruit employees for Google in China and to talk to government officials about licensing, but was prohibited from working on technologies such as
search or
speech recognition. Lee was also prohibited from setting budgets, salaries, and research directions for Google in China until the case was to go to trial in January 2006. Before the case could go to trial, on December 22, 2005, Google and
Microsoft announced that they had reached a settlement whose terms are confidential, ending a five-month dispute between the two companies. He also strengthened the company's teams of engineers and scientists in the country. On September 4, 2009, Lee announced his resignation from Google. He said "With a very strong leadership team in place, it seemed a very good moment for me to move to the next chapter in my career."
Alan Eustace, senior Google vice-president for engineering, credited him with "helping dramatically to improve the quality and range of services that we offer in China, and ensuring that we continue to innovate on the Web for the benefit of users and advertisers". Several months after Lee's departure, Google announced that it would stop
censorship and move its
mainland China servers to
Hong Kong.
Sinovation Ventures In September 2009, Lee announced details of a $115 million venture capital fund called Innovation Works (later changed to "
Sinovation Ventures"), a Beijing‑based incubator and venture fund focused on early‑stage internet and mobile startups. The firm raised successive funds through the 2010s that emphasized AI‑related investments.
01.AI In March 2023, Lee founded
01.AI, an artificial intelligence startup focused on
large language models (LLMs) for the Chinese market. In November 2023 the company released its first open‑source model, Yi-34B. In January 2024, the company introduced a multimodal model, Yi‑VL‑34B. In February 2025, Lee said 01.AI formed a joint lab with
Alibaba to advance LLM technologies. In March 2025, the company launched
Wanzhi, an enterprise platform for deploying AI applications. == Recognition ==