1. Random team/location placement
2. Legacy tech/legacy code
3. Management undermines college graduate skillset. My primary task for 6 months was to maintain an excel spreadsheet of unix server passwords. I've pushed this horrible experience behind me and have moved on. However, I don't want any college graduate to experience the same as I did. If you're a college graduate and want rapid growth in your career, then don't work here.
4. Fannie Mae hires lots of contractors, so people come and go all the time.