Giancarlo holds a bachelor's degree in electrical engineering from Brown University, a master's degree in electrical engineering from the University of California at Berkeley and an MBA from Harvard University. He co-founded Telecom Systems in 1984, and then Adaptive Corporation in 1988.
Giancarlo joined Cisco in 1994 when it acquired Kalpana, an Ethernet switching company, where he was vice president. He became Cisco's first vice president of business development, where he developed Cisco’s merger and acquisition strategy and practice. In 1999 he took responsibility for the commercial line of business at Cisco, became chief technical officer in 2003 and chief technology officer in July, 2004. Giancarlo was responsible for many of Cisco’s technologies including Ethernet switching, Wi-Fi, security, IP Telephony, and telepresence, as well as Cisco's entry into markets such as the small and medium business and consumer markets after acquiring Linksys, Scientific Atlanta and WebEx. Although some analysts thought he might become chief executive after John T. Chambers, Giancarlo resigned from Cisco in December 2007.
In January 2008 he became a managing director and operating partner at the private equity firm Silver Lake Partners. He was president and CEO of Avaya from June, 2008 (replacing Louis D'Ambrosio), through December 2008 . After the appointment of Kevin J. Kennedy as CEO, he became chairman of the board at Avaya, while continuing to serve at Silver Lake. 
- "Charles Giancarlo Biography". Cisco. Archived from the original on March 8, 2007. Retrieved October 4, 2016.
- Matt Hamblen (July 14, 2004). "Cisco promotes Charles Giancarlo to CTO: It announced several changes to its leadership team". Computer World. IDG News Service. Retrieved October 4, 2016.
- "Charles H. Giancarlo" (PDF). Copy of corporate biography. David Chao. March 2, 2007. Retrieved October 4, 2016.
- Andrew R. Hickey (December 21, 2007). "Giancarlo departure won't hurt Cisco - Yet". CRN. Retrieved October 4, 2016.
- Stephen Lawson (December 20, 2007). "Key Cisco leader Giancarlo steps down: was seen as the heir-apparent to Chambers". Computer World. IDG News Service. Retrieved October 4, 2016.
- "Cisco's heir-apparent Charles Giancarlo resigns". USA Today. Associated Press. December 20, 2007. Retrieved October 4, 2016.
- "Avaya CEO Charles Giancarlo to Keynote VoiceCon San Francisco 2008". Press release. Avaya. October 31, 2008. Archived from the original on November 10, 2008. Retrieved October 4, 2016.
- "Lou D'Ambrosio to Step Down as Avaya CEO and President for Medical Reasons". Press release. Avaya. June 9, 2008. Retrieved October 4, 2016.
- Kevin Kennedy to Join Avaya Inc. as President and Chief Executive Officer
- Giancarlo identified in 2012 in top 50 deal makers. Forbes Online, October 3, 2012
- "Charles Giancarlo, Managing Director, Silver Lake". YouTube video of A. Richard Netwon Distinguished Lecture Series. UC Berkeley. October 6, 2009.
- Equinix, Blue Jeans Networks, Coraid, Big Switch Networks, Avi Networks, Soraa, Enlighted, Attivo, Exablox, Formation Data, LensVector, NetSpeed, Virtual Instruments, Mercury Payment Systems and Vantage Data Centers
- "Accenture Appoints Charles Giancarlo to Its Board of Directors". Press release. Accenture. December 16, 2008. Retrieved October 4, 2016.
- "Charles Giancarlo joins Tintri Board of Directors". Press release. October 4, 2016. Retrieved October 6, 2016.
- "CYBERATTACK INVESTIGATION:CHARLES GIANCARLO". Congressional Testimony. February 29, 2000. Retrieved 3 Sep 2011.
|EVP, Chief Development Officer
|President & CEO
Kevin J. Kennedy
John R. Joyce
|Managing Director, Head of Value Creation
Silver Lake Partners