Mike George, the Amazon vice president who oversaw two of the company’s most successful products — the Alexa virtual assistant and Echo smart devices — is leaving after nearly two decades with the Seattle-based tech giant.

George’s LinkedIn profile now lists him as “retired” with one of the nerdiest farewell messages ever: a long post in binary code that translates to, “Retired from Amazon after ~20 years. Loved every minute. Not checking out, just changing the game :-)”

George will be replaced as the Echo and Alexa chief by Tom Taylor, a senior vice president who has been running the Amazon Payments and Fulfillment By Amazon (FBA) businesses. George also ran the Amazon Appstore, but that part of the business has been shifted to Amazon’s Devices & Services organization, under senior vice president Dave Limp.

GeekWire learned of the changes via a tip this evening and was able to confirm them independently. Amazon isn’t commenting publicly on the news, and George hasn’t responded yet to a request for comment on his departure.

George joined Amazon in 1998, serving in a variety of roles ranging from General Manager of Seller Platform Integration to vice president of Global Payments Services, and later Vice President of Apps, Games and Cloud Drive, among many other roles. He has led Alexa and Echo since January 2016.

Under his leadership, Amazon’s Alexa voice-enabled assistant and Echo speakers have been runaway hits. The company is battling other tech giants like Google, Microsoft, and Apple in the competitive voice assistant market, though it has a big lead as the first mover. A recent forecast from eMarketer estimates that Amazon will have a 71 percent market share of all voice-enabled speakers in the U.S. this year.

In an interview with GeekWire in December, George said Alexa’s capabilities were just getting started.

“She’ll be smarter, able to answer more questions, probably a little more conversational,” he said at the time. “She’ll have many more capabilities, from us and from third parties. You’ll see Alexa manifest herself on more and more of other people’s hardware, doing more and more things.”

Alexa powers Amazon’s Echo devices. The original Echo is the flagship member of the Alexa family, with other models like the smaller Echo Dot and the portable Amazon Tap. Amazon has since branched out with the announcement of several new Alexa-powered devices: the fashion-oriented Echo Look; the Echo Show with touchscreen; and most recently the $20 Dash Wand.

Amazon doesn’t say how many Alexa-powered devices it has sold, but a recent report by Consumer Intelligence Research Partners puts that figure at 10.7 million, with close to half of those coming between November 2016 and March of this year.

Alexa’s proliferation across both Echo devices and third-party products can be partially attributed to Amazon’s decision to open the digital brain up to developers and device manufacturers in 2015. Alexa Voice Service lets manufacturers integrate Alexa into their products. The Alexa Skills Kit encourages third-party developers to build skills for Alexa. Developers who want to add to Alexa’s abilities can write code that works with Alexa in the cloud, letting the smart assistant do the heavy lifting of understanding and deciphering spoken command.

Alexa’s skill count passed 15,000 in the U.S. at the end of June.

According to a report in The Information this week, Amazon may soon open up audio transcripts saved by Alexa-powered devices for third-party developers.

Here’s our message to Mike George: 01010111 01101000 01100001 01110100 00100111 01110011 00100000 01101110 01100101 01111000 01110100 00100000 01001101 01101001 01101011 01100101 00111111 00100000 01000111 01100101 01100101 01101011 01010111 01101001 01110010 01100101 00100000 01110010 01100101 01100001 01100100 01100101 01110010 01110011 00100000 01110111 01100001 01101110 01110100 00100000 01110100 01101111 00100000 01101011 01101110 01101111 01110111 00101110