-Cross-org transfer is not something that is in practice supported. In theory, "yes." In practice, rare. Instead, once you're in your seat, you're pretty much stuck in that seat for a while. Upward career mobility is merit-based, though slow, however if you come in as a developer, and wish to move to Services, or vice-versa, the challenges of doing so are higher than average compared to other companies. Most people just give up and quit. Be absolutely sure you want to be a "developer," or a professional services engineer, or a sales person for 5+ years -> forever. This may ease up at some point, though was not the case when I left.
-Demands of the company can grown very fast, with some waning at times. Hiring is sometime matches the demand, other times painfully behind, other times a bit ahead. There are other factors too such as budget, and investor pressures. Crunch mode can come really fast, and then a lull, and then fast again.
-Salary increases have been woefully small in the last couple of years.
-Office musical chairs seem to be happening every six months. Don't bring in expensive art work or nice furniture.