Pros
It's a great company to work in with a nice (more like startup) atmosphere. They request and meaningfully act on feedback. The company tries to be transparent, you can ask anything to anybody. I get to spend my days working with smart, passionate people. I've solved challenging technical problems and am supported and encouraged by those around me to stretch out of my comfort zone and learn more. I can manage a good work/life balance which is really important for me.
Cons
There are definitely more pros than cons. I can only think of those offline cons: You get different benefits, equipment etc. depending on if you work for Barcelona office or for Warsaw office. Those in Warsaw are not so great compared to other companies here. Location of the office in Warsaw is the biggest downside, there are not many food places around, the area is not pleasant or nice place to be if you don't arrive by car (of course it doesn't matter if you're working remotely).