Company profile of T-Systems International GmbH, one of the leading ICT specialists headquartered in Frankfurt/Main
Board of Management

Board of Management

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Senior VP, Sales Region Americas and Managing Director
North America

Paul Warrenfelt

Paul joined T-Systems through the acquisition of gedas which was fully integrated into T-Systems International in April 2006. He has more than 25 years of industry experience and over 10 years of international senior leadership experience.
Prior to gedas and T-systems, Warrenfelt served in a number of senior positions in the consulting, information technology and manufacturing industries, supporting major client accounts.  He has extensive experience in managing diagnostic and system development projects; implementation of SAP applications; and data center management.  Warrenfelt has had a great deal of experience in the development and sponsorship of customer relationship and leadership programs throughout his career.
Warrenfelt received his Bachelor of Science degree in Mechanical Engineering in 1978 from Purdue University and a Master of Science degree in Computer Aided Manufacturing in 1983 from Brigham Young University.  He went on to achieve a Master of Business Administration with specialization in Information Systems from Indiana University in 1987.
Vice President, Finance and Controlling
Member of the Management Board
T-Systems North America

Bertus Cilliers

Bertus Cilliers serves as Vice President, Finance and Controlling for T-Systems North America. In his role, he is responsible for all financial activities of T-Systems North America.  Mr. Cilliers focuses on internal IT, accounting, controlling, procurement, legal and pricing activities.  
Prior to joining T-Systems in 2009 Mr. Cilliers was a Senior Commercial Manager for Services with Wincor Nixdorf in the UK. He was promoted to the Senior Commercial Manager position in less than 12 months of being with the company. Some of his responsibilities at Wincor Nixdorf included providing the overall financial support and strategic guidance for Services, contracting negotiations with major accounts in the UK and overall financial management of the service division to reach revenue and gross profit targets.  
Previous to his position at Wincor Nixdorf Mr. Cilliers was a Business Finance Manager and then moved on to become the Head of Controlling for T-Systems in the UK. While part of T-Systems UK he was involved in the successful installation of the SAP Financial systems and an integral part of the team which ensured successful turnaround and profitability. 
Mr. Cilliers holds Bachelors degree in Accounting form Rand Afrikaans University and a MBA from the University of South Africa.

Vice President, Human Resources
Member of the Management Board
T-Systems North America

Stepan Marzini

Stepan has been with Deutsche Telekom AG since May 2007. He began his tenure with Deutsche Telekom at T-Mobile Czech Republic as the Senior Head of Human Resources Business Partner team supporting the Technology Division.
In 2011, he became Vice President of HR Management, responsible for the whole Business Partner (BP) unit and HR Back Office services. In 2016, he was supporting both T-Mobile Czech Republic and Slovak Telekom as HR BP Director for Technology and Supporting Functions. In April 2017, he transitioned from Telecommunications to IT and became Vice President Human Resources, T-Systems North America.
Vice President, Delivery
Member of the Management Board
T-Systems North America

Cesar Martinez

Cesar Martinez serves as Vice President, Delivery for T-Systems North America. In his role, he is responsible for the delivery of customer oriented ICT/SI services and solutions at top quality.
Cesar has been with T-Systems since 2000. He started in Mexico as General Counsel and moved to the US where he held various positions including Senior Controller for T-Systems North America and Service Region Americas Program Manager and Operations Manager. In addition, Cesar served as Acting Vice President of ICTO for Argentina, Brazil, and South Africa where he was responsible for delivery of ICT Services, cost control, quality and service improvement. Cesar comes to T-Systems North America s from his most recent role as Vice President of Delivery at T-Systems France during which time he led the operations and service areas, provisioning customers such as Airbus, Gemalto, Yves Rocher and Daimler among others. In addition, he successfully lead the transformation of Delivery to align with TSI Delivery Strategy, making France a model Point of Delivery in the EMEA Region.