Pros
For a junior professional, Helloprint is the best company to work for. You will get a chance to pick up different skills and technologies. Your colleagues are very helpful. The technological stack is also very interesting: google cloud, Alteryx, Neo4j... And lastly, for those who like to be social with their colleagues, Helloprint encourages this and always delights people with new events.
Cons
The company does not seem to be able to keep one direction. New projects keep coming up, while current projects are hardly finished. From what I've seen in my team, not even one Scrum sprint was fully done. That is because this company is managed on ad hoc basis. That makes planning hard. In short: it still feels like a startup, but it shouldn't be. The management makes it so.