Great companies start with an awesome team
OX Leadership Team

At Open-Xchange, leadership is more a mindset than a title. The nature of our organization is geared towards a flat hierarchy and an open way of working together. The leadership team supports this approach through a mix of business expertise, entrepreneurial experience and operational know-how. Our culture encourages an open approach – exploring, experimenting and mixing things up. You can see the results everywhere – in our people, in our partners and how we develop multi-cultural teams.      

OX Supervisory Board

Richard Seibt
Chairman of the Supervisory Board

Richard Seibt has over 35 years’ experience in the IT business and became Open-Xchange Chairman in 2006. As Managing Director at IBM Germany, he handled sales and marketing in Germany, Austria, Switzerland and Eastern Europe. He then worked for IBM North America as VP Software Sales and Marketing and as General Manager worldwide for the OS/2 operating system. In 1998, he became an Executive Management board member at United Internet. In 2003, Seibt was appointed CEO at SuSE Linux and in 2004 (following the company’s acquisition by Novell), he became President of Novell Europe, Middle East and Africa. Since leaving Novell in 2005, he has been working as a business angel and board member for several other IT companies.


Achim Weiß

Achim Weiß is the CEO of IONOS, where he is responsible for the company's overall strategy and product development. Weiß has more than 20 years of experience in the European internet industry and in 1995 co-founded Schlund + Partner, the German web hosting pioneer that was taken over by 1&1 in 1998. As Chief Technology Officer at 1&1 until 2008, Weiß developed, amongst other things, the world's first web hosting platform for the rapidly growing mass market. As one of the leading experts in the field of developing scalable internet infrastructures, Weiß founded ProfitBricks, the first German cloud infrastructure solutions (IaaS) provider in 2010. After 1&1 acquired ProfitBricks in 2017, he returned to the board and was appointed CEO of IONOS in October 2018.


Dr. Marcus Gulder

Marcus Gulder has been Head of Venture Capital at BayBG Bayerische Beteiligungsgesellschaft since 2012. Gulder played a leading role in building up the VC activities of BayBG from zero to EUR 50 million in 2017. BayBG is focused on investments in Bavarian Tech and SME companies with EUR 320 million capital under management. During Gulder’s 15 years in the VC scene he has led numerous investments, including Medical Intelligence (acquired by Elekta), CAS innovations (acquired by Siemens), SiC Processing (Secondary to Nordic Capital), Activaero (acquired by Vectura Group) and ubitexx (acquired by Blackberry).


Curt Gunsenheimer

Curt Gunsenheimer, Senior Partner at Iris Capital, joined the company in 2002. He is responsible for investments in late-stage and growth capital across Europe and supports companies across Germany and France in stages of global expansion. Gunsenheimer has twenty years of experience in venture capital and public-market financing of growth technology companies, with particular expertise in the field of software. Prior to joining Iris Capital, he worked at Goldman Sachs and Robertson Stephens.


Dr. Paul-Josef Patt

Dr. Paul-Josef Patt is CEO of eCAPITAL entrepreneurial Partners, a German venture capital company. He has worked as a Project Manager at Roland Berger & Partner, the leading German strategy consultancy and as Director of Corporate Strategy at Kaufhof Holding, managing the expansion of one of Germany’s biggest retailers. After his successful exit, Patt started working as a business angel and venture capitalist. He took over the lead at eCAPITAL in 2004 and has overseen the company’s impressive growth. He has a strong track record in financing and developing young high-tech companies and as lead investor, initiated the sale of Novaled to Samsung in 2013 – at that time, the largest venture capital deal in the German hi-tech sector. Patt serves on several boards, including sonnen, Jedox AG and Heliatek.

Bernhard Wöbker

Bernhard Wöbker worked as CEO and president at Nixdorf USA during the company’s expansion in the US before moving on to hold leading positions at Pyramid, NeXT and Versant, a listed US enterprise software company. He also worked as a consultant for Warburg Pincus, one of the largest US private-equity investors. Recently, Wöbker headed Munich-based software provider Brainloop. He now serves as Chairman of the Supervisory Board at the business intelligence provider, Jedox.



Looking for a new challenge?

Join the OX team

Current Jobs
Andreas Gauger andreas_gauger_800x800

Andreas Gauger
Chief Executive Officer

OX's CEO Andreas Gauger has been heavily involved in shaping the cloud and...

read more >
Frank Hoberg Frank Hoberg

Frank Hoberg
Chief Sales Officer

Hoberg co-founded Open-Xchange together with Rafael Laguna (now Director SprinD...

read more >
Carsten Dirks carsten_dirks_big

Carsten Dirks
Chief Operating Officer

Dirks is responsible for engineering, research & development and daily...

read more >
Dirk Valbert Dirk Valbert

Dirk Valbert
Chief Financial Officer

Valbert is responsible for Finance, Legal and Corporate Services at...
read more >
John Broomfield John_Broomfield_big

John Broomfield
VP Marketing

Broomfield is responsible for setting the strategic direction and operational...

read more >
Stephan Martin stephan_martin_big

Stephan Martin
EVP Services

Over the past 10 years, Martin has built Open-Xchange’s professional services...

read more >
Bob Krulcik bob_krulcik_big

Bob Krulcik
SVP, Sales & Business Development - The Americas

Krulcik is responsible for the strategic direction and execution of...

read more >
Bob Brandt Bob Brandt

Bob Brandt
VP, PowerDNS Engineering, PowerDNS

Brandt manages the PowerDNS Engineering team and is ultimately responsible for...

read more >
Timo Sirainen Timo Sirainen

Timo Sirainen
Creator & Chief Architect, Dovecot OY

Sirainen programmed the Dovecot IMAP Server in 2002, releasing the first...

read more >