Yes, Janis is my first name. We did a little research using eazyBI and found out that it is indeed quite common among our employees as you can see in the chart. 
Furthermore, if you take into account that Janis is a male, the percentage of male employees in eazyBI is 61.5% 
Janis is John in English. It’s a popular first name all troughout the Europe and the World. I believe in Poland it’s Janek or Janusz, but there are many other treanslations.