While in high school, Cerf worked at Rocketdyne on the Apollo program for six months and helped write statistical analysis software for the non-destructive tests of the F-1 engines.

He wrote the first TCP with Yogen Dalal and Carl Sunshine, called Specification of Internet Transmission Control Program (RFC 675), published in December 1974.

Previously, he served as MCI's senior vice president of Architecture and Technology, leading a team of architects and engineers to design advanced networking frameworks, including Internet-based solutions for delivering a combination of data, information, voice and video services for business and consumer use.

[5] In this function he has become well known for his predictions on how technology will affect future society, encompassing such areas as artificial intelligence, environmentalism, the advent of IPv6 and the transformation of the television industry and its delivery model.

Speaking as Google's Chief Internet Evangelist, Cerf noted that nearly half of all US consumers lacked meaningful choice in broadband providers and expressed concerns that without network neutrality government regulation, broadband providers would be able to use their dominance to limit options for consumers and charge companies like Google for their use of bandwidth.

[48] Cerf currently serves on the board of advisors of Scientists and Engineers for America, an organization focused on promoting sound science in American government.

[50] Cerf was elected as the president of the Association for Computing Machinery in May 2012[51] and joined the Council on CyberSecurity's Board of Advisors in August 2013.

[52] From 2011 to 2016, Cerf was chairman of the board of trustees of ARIN, the Regional Internet Registry (RIR) of IP addresses for the United States, Canada, and part of the Caribbean.

[53] Until Fall 2015, Cerf chaired the board of directors of StopBadware, a non-profit anti-malware organization that started as a project at Harvard University's Berkman Center for Internet & Society.

[54][55] Cerf is on the board of advisors to The Liquid Information Company Ltd of the UK, which works to make the web more usefully interactive and which has produced the Mac OS X utility called 'Liquid'.

[59] Cerf is the co-chair of Campus Party Silicon Valley, the US edition of one of the largest technology festivals in the world, along with Al Gore and Tim Berners-Lee.

SGIP is a public-private consortium established by NIST in 2009 and provides a forum for businesses and other stakeholder groups to participate in coordinating and accelerating development of standards for the evolving Smart Grid.

[66] In June 2016, his work with NASA led to delay-tolerant networking being installed on the International Space Station with an aim towards an Interplanetary Internet.

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