Pros
Some really interesting technology and acquisitions. Opportunities for travel. Really great coworkers (at least in my immediate team). One of the best bosses I have ever worked for, seriously. Remuneration was overall pretty good, there's better out there in the industry though.
Cons
Them and us atmosphere between long termers / pre-IPO guys and newer recruits, cliquey as others have said. Knowledge sharing is horrible/non-existent which without a doubt costs hundreds or thousands of hours of wasted time as everybody has to burn through the exact same processes/failures as colleagues already did because there's no way to share what you know beyond your immediate colleagues. Insane levels of secrecy/paranoia/outright hostility between colleagues in different departments / countries leads to extreme bunker mentality, this is poisoning the atmosphere and costing time and money. Next to no forward communication from upper/senior management about direction, troops on the ground find out about things at best around the same time that the customers do, not cool if you are sat with that customer at the time. Company is rich and profitable but can be painfully cheap - enforced room sharing as standard with colleagues you barely know on international trips (ugh) and quibbling over the tiniest expenses. Bonus structure is complex and not worth writing home about in reality. Promises get made at interview that are forgotten once you're in the door because low headcount is a constant pressure (turnover). Releases are increasingly shipping that have pretty fundamental bugs in. Huge pressure from the commercial guys to do whatever will help them to get their next bonus check, not what is best for the customer or the company longer term. This is a lawsuit waiting to happen.