Pros
The culture was fun and there were a lot of really smart people working there (most have left already after the Oracle acquisition). There was free daily catered lunch, projects were interesting if you were on the right teams, and pay was decent, but below what you could earn at FAANG.
Cons
After the acquisition, things went downhill fast. Lots of brain-drain with some of the best, most driven employees seeking other opportunities at smaller, fast growing startups. We lost our free daily catered lunches after a while, which was disappointing but expected since it would be unfair for AddThis to get free lunch while other teams in the same office building did not. Oracle culture is pretty typical big-company - things move slow, tons of bureaucracy, and lots of legal red tape, though AddThis was shielded from some of that. The teams skewed towards the younger side and there was definitely a "bro" feeling with some teams which could be a turnoff to some. Overall, I had a good experience at AddThis, but that definitely turned for the worse once we became part of the ODC.