Pros
The core business idea is beautiful: solving real world problems with mathematics. This was my first job out of university and I assumed the management structure must be normal for industry. I have since learnt that it is definitely not normal and hopefully I can avoid finding myself in a similar structure ever again. I guess that's a positive thing to take away. When management weren't interested in the technical side of the projects, we had a fun time doing research and that was amazing. I'd like to be part of a team like that again. It felt really great when I left! Even better than finishing my PhD.
Cons
The management is the CEO and the CTO. Everybody else is equally beneath them. The CTO is the husband of the CEO and there is a huge age gap with the researchers. Basically, everybody is scared to stand up to them. When management got involved in projects there was a really bad communication problem. I couldn't understand anything that the CTO was talking about. He didn't seem to understand basic mathematics, but he was absolutely certain that we were all wrong and he would get very emotional and sometimes shout at us. He also seemed to obsess about small details of our lives and often we'd have to congregate around him so he could lecture at us (sometimes for hours) about how to live our lives according to his own philosophy. It was actually very weird and he never gives solid facts or references to anything he says, it had the feel of a cult. I never got to communicate directly with customers. I imagined it being very customer focused, but we were kept in the dark all the time. To be honest, I think the paid work was drying up and we were just working on the CTO's pet projects until something came along. I never got to see any of our solutions put into practice, it was just all abstract "what if?" research, which was not as rewarding as it could have been. I wanted to see my algorithms doing something for real, not just rotting in a computer hard drive.