I’m a long-term .NET developer with a passion for mobile apps. I started programming in Turbo Pascal and x86 assembler back in the 1990s. Later, I studied and achieved my MSc in Computer Science. Over the years, I have learned that C# is the language I love most. Combined with my passion for smartphones, the logical consequence was to use Xamarin. Today, I am working as a trainer at Microsoft for Xamarin.University and help others successfully create cloud connected cross-platform apps.

Let’s stay in touch

You can find me on Twitter: https://twitter.com/rene_ruppert

profile for Krumelur at Stack Overflow, Q&A for professional and enthusiast programmers

Github: https://github.com/krumelur

What’s that URL “c-sharX.net” all about?

In 2013 I decided to become self employed and started my business that would focus on C# based cross platform apps using Xamarin technology. Combining C# and the “X” from Xamarin resulted in c-sharX (which is by the way a registered brand). Also, one simply has to have an “X” in the name, otherwise you won’t be taken seriously in the dev community, right? 😉

What is a Krumelur?

I do not exactly know. But here’s the story behind it being my avatar: when I was grumpy my wive told me to stop grumbling and in German she used “grummeln” and she said I was a “Grummelur”. Later while shopping at IKEA we found a cushion/animal called “Krumelur” and she said “look, that’s you!”. That’s when I started using it as a nick name.

Fun fact: one of my former coworkers from Finland once explained that “krumeluuri” would be useless stuff one has at home…

IKEA’s Krumelur


René Ruppert