Dennis Zimmer is a renowned virtualization expert with a special focus on Server virtualization of large environments. He is a published author of best-selling books, articles and training videos for virtualization technologies and a popular keynote speaker for industry events, including VMworld Europe, where his session was awarded best of show and most attended (3 sessions, ~1000 attendees.)

In 2012, Dennis co-founded opvizor Inc. in Houston, TX, USA, offering a complete new Software-as-a-Service Virtualization solution that automates expert knowledge to predict issues in a virtual infrastructure before they emerge. Today, opvizor helps more than 1,000 system administrators and consultants in global enterprises avoid costly damage and optimize their virtual environments (VMware vSphere, VMware vCenter) including ESXi hosts and virtual machines. He currently acts as CEO of opvizor.

Prior to establishing opvizor, Dennis co-founded icomasoft AG in Switzerland and worked on a wide range of high-profile projects in the virtualization field, including spearheading consulting projects for companies such as Siemens, OBI, Deutsche Bank, Migros, Unicredit, and more. During this time he also developed a successful product, VI PowerScripter, which was later sold to DevFarm. Prior to going independent, Dennis worked for companies such as Pillar Data Systems and Mightycare Solutions (VMware Premier Partner).

Dennis is a thought-leader and pioneer in his space. In 2006 he founded the first VMware usergroup in Germany and in 2010, he founded the NetApp usergroup Switzerland. Through his blogging and writing efforts, he has been awarded the title of VMware vExpert eight years running, an honor only 50 people worldwide have achieved. He has published 10 books total, 6 of which have been bestsellers.
Dennis graduated from Advanced Technical and Business College in Germany at the age of 18.