Can be good or bad experience - depends in which group you're in. I've had both.
Pros
If you can get into a certain teams, Syniverse can be a superb employer - interesting work, huge challenges, flexible schedules, working from home, good compensation, etc. Overall, the company has been improving most of it's software environment, and seems to have learned a few hard lessons about trying to outsource too much. Under certain superstar VPs, the bonuses can even be generous!
Cons
However, there are still big chunks of the company where technical staff are working on big bloated applications, under unimaginative supervisors, using horrible out-of-date tools. There's still an awful lot of electronic forms to get things done (extra disk space added to servers, creating new user accounts, even swapping out a $10 ethernet cable). Mobility from the boring groups to the exciting group is nearly impossible to achieve.