Pros
Really friendly atmosphere and helpful friends. Nice physical environment. Getting real-time application experience. Getting domain know-how.
Cons
Small tech stack. Overworking, no work life balance. Slack, whatsapp never stops even at evening. You can be called on the weekend. There is no support team. They don't think to do that, it's not in their plan. That's why developers take turn do this during service hours. Including the weekend. Inexperienced and extremely young managers. When you ask this explicitly, they don't give a clear answer but they want you to sign a contract for have right on the codes you have developed, even if it's not for the company ( for example open source or your special project ). Terrible human department.