Buchheit joined Google early in its history as employee number 23. This put him in a unique position to directly contribute to the company's growth and development during its formative years.

Buchheit is best known for creating Gmail. Frustrated with the existing email options, he developed Gmail as a '20% time' project, revolutionizing email with its large storage capacity, search capabilities, and innovative interface. He initially named the project 'Caribou'.

Buchheit played a significant role in the development of AdSense, Google's advertising program. AdSense revolutionized online advertising by allowing website owners to generate revenue by displaying targeted ads on their sites, based on the content. This was a key contribution to Google's revenue model.

Buchheit was instrumental in fostering Google's unique company culture, especially through his contributions to the '20% time' program. He consistently advocated for employee innovation and experimentation, fostering a dynamic environment that fueled creativity and technological advancement within Google.

Buchheit departed from Google to pursue new opportunities, including starting his own companies. His tenure at Google left a lasting impact on the company and the tech industry.