From the rules[1]:
"The six teams that fight their way to the finals will receive a four-day, all-expenses paid trip to Helsinki, Finland. The trip will include great company, delicious food and one heck of a tour in the capital city of Finland."
Yes. Sorry, I was reading below, but that was another event:
"All six finalist teams will get exclusive tickets to the to-be-sold-out tech conference of the year Reaktor Dev Day, worth 500e/piece. More information on the conference. Travel and accommodations costs are not included."
[1] https://helloworldopen.com/rules