Pros
Friendly atmosphere. Good culture. Very junior, which makes it fun. Straightforward communication. Exponential growth which means a lot of opportunities to get a job. (Though it's hard have career progression in the company if you don't know "The right people".)
Cons
It's still a new company, and the people working here doesn't have a lot of years experience. It's either their first or second job. This includes the people in management.. At this time, 2015, iZettle is behind on company benefits compared to other companies. The salaries are low compared to other companies, and they get away with it since most of the staff is entering on a "junior" level since it's their first job. But the salaries does not go up with the experience. Last year, no one got a raise. At other companies, you always get a certain percentage, at least. No career progress in the company, unless you know "The right people". Friendly atmosphere, but also means that it's friends that get promoted, and not so much based on performance.