Pros
People. Flat structure. I, as Intern, have no problem asking C-level for help, if the issue is important. Culture in the company is friendly and nobody would blame you for mistake, but you should still avoid making the same mistake more than twice. People don't play politics in the office, which was very unusual and took me 2-3 months to adjust, because every single environment I've ever been in required playing politics to a certain extent. Here it doesn't exist, people are very direct and just work.
Personal mentorship. It has taught in 3 months approximately as much as school, university and college taught me in 15 years.
Compensation. I was offered project management internship position in Allianz and they offered the same money.
Place. Berlin is awesome. Office space is good too. Tech is not a problem. If you need a phone for work - you get a phone.
Cons
Occasional lack of structure because the company grew so fast. You need to do a lot of prioritization, because there are million things, which you would like to develop and improve, but losing focus may have a pretty high impact.