About the Reviewers

Hakan Hansson has worked as a QlikView developer and architect since 2007, when he was introduced to version 8. He has worked with the data management, integration, and design of QlikView applications in many different environments and in fields such as sales, logistics, and finance.

Currently, Hakan is working as a senior consultant at Climber (http://climber.eu), which is the largest Qlik partner in Europe with experts in seven countries. Their services range from developing brand new dashboards and knowledge transfer to maintenance and support.

Speros Kokenes is a data visualization practitioner with several years of experience in bringing visualization best practices to QlikView applications. He has received several awards from Qlik for his dashboard design and development work. Speros leads a design team at Axis Group, an information management consulting firm that is North America's largest focused Qlik development organization. He writes about data visualization at http://blog.axisgroup.com.

Karl Pover is a Qlik Luminary and president of Evolcon Evolution Consulting (http://www.evolcon.com), which provides QlikView consulting services throughout Mexico. Since 2006, he has been dedicated to providing QlikView presales, implementation, training, and expert services. Karl is the author of Learning QlikView Data Visualization and the soon to be published Mastering QlikView Data Visualization.

You can follow him on Twitter at @karlpover and read his blog at http://www.poverconsulting.com.

Mark O'Donovan is a QlikView developer and author based in London, England. He has over 20 years of experience in the IT industry and has been working on SQL Server Business Intelligence projects since 2008. Mark has been using QlikView since version 9.

He has had an interest in visualization since his student years; his master's degree thesis called "Towards a methodology for visualizing quantum computing" was presented as part of a EuroGraphics conference at Imperial College, London, in 1996.

Mark has been an active member of the Qlik Community since October 2011 and has been the author/publisher (TechStuffy Books) of the following books on Qlik and SQL:

• Qlik Sense for Beginners

• Practical QlikView

• Practical QlikView 2 - Beyond Basic QlikView

• Practical Sql: Microsoft Sql Server T-SQL for Beginners

Here are some useful links to his content:

• http://techstuffy.tv (YouTube—regular videos on QlikView, Qlik Sense, and SQL)

• http://techstuffybooks.com (Books on Amazon)

• http://udemy.com/u/markodonovan (Video training)

• http://techstuffy.com (Blog and free book samples)