Thomas Seifert

Chief Financial Officer Cloudflare

Last Reviewed: October 1, 2026

Executive Summary

Thomas Seifert has been Chief Financial Officer of Cloudflare since June 2017, and was the finance chief who took it public in 2019. He arrived with long public-company experience. He had already been chief financial officer of the chipmaker AMD, the wireless distributor Brightstar and the security software company Symantec. At AMD he also ran the whole company for eight months in 2011 as interim chief executive. At Cloudflare he has overseen the finances of a business whose revenue passed $2 billion in 2025.

Career Highlights

• Chief Financial Officer of Cloudflare since June 2017.
• Executive Vice President and CFO of Symantec from March 2014 to November 2016.
• Executive Vice President and CFO of Brightstar Corp. from December 2012 to March 2014.
• Senior Vice President and CFO of Advanced Micro Devices from October 2009 to September 2012, and its interim CEO from January to August 2011.
• Former director of Wolfspeed, IPG Photonics and CompuGroup Medical.

Professional Journey

Seifert studied in Germany and the United States. He earned a B.A. in business administration and an MBA at Friedrich Alexander University, and an M.A. in mathematics and economics at Wayne State University.

In October 2009 he became Senior Vice President and Chief Financial Officer of Advanced Micro Devices, the semiconductor company. From January to August 2011 he also served as its interim chief executive. He left AMD in September 2012. In December 2012 he became Executive Vice President and CFO of Brightstar Corp., a wireless distribution and services company.

In March 2014 he moved to Symantec, the cybersecurity software provider, as Executive Vice President and CFO. He held the role until November 2016 and then advised the company until March 2017.

Cloudflare hired him as Chief Financial Officer in June 2017. Two years later the company completed its initial public offering, in September 2019. Since then he has run its finances as revenue has grown to $2.17 billion in 2025, up 29.8 percent, with $603.1 million of operating cash flow that year. In the second quarter of 2026 revenue rose 36 percent to $696.1 million.

He has also served on several outside boards. First Derivatives plc, now FD Technologies, appointed him a non-executive director in July 2020. He joined the board of IPG Photonics, the fibre laser manufacturer, in early 2023, and was previously a director of the eHealth company CompuGroup Medical. He joined Wolfspeed’s board in December 2024 and resigned from it on 3 April 2025.

Education

Friedrich Alexander University

B.A. and M.B.A., Business Administration

Wayne State University

M.A., Mathematics and Economics