Mattheisen has more than two decades of working in senior leadership roles in telecommunications and IT. He started his career launching Westel 900 (predecessor of T-Mobile) in Hungary, and moved on to marketing, sales and strategy roles at other operators in Europe, including Era GSM in Poland, MediaOne International, BT Cellnet (O2), as well as two IT startups in the U.K. and U.S.

Mattheisen returned to Hungary to run the fixed-line business of Magyar Telekom in 2002, before his promotion to CEO in 2006. He led Telekom successfully for 12 years until 2018. 

"This is a truly exciting time to join the Microsoft team. Emerging technologies such as Cloud, Big Data, Internet of Things, Artificial Intelligence, and even Augmented/Virtual Reality are now becoming mainstream, and Microsoft can claim a leading position in each of them," Mattheisen said.

"In my new role, I look forward to helping Hungarian businesses and organizations take full advantage of the opportunities created by these technologies," he added.