A lot of the Internship "Lunch and Learn" sessions or informational meetings that HR put together are helpful, but can hinder your work performance if you attend to many. While they are optional, it feels as if you are missing out on the Internship experience if you do not attend them. However, I had trouble keeping up with certain tasks because of the frequency of those meetings.
There was this awkward internship video we were assigned early on in the year. We were supposed to cast a few employees to talk about various things based on the topic the coordinators assigned. We were very proud to have had the CEO (Jim Peck) agree to do a piece in our video -- only to have it taken out and put into another team's video. What made matters worse is no one told us about the change until the showing. After inviting several of our department managers to the showing, a lot of them left confused as to why he wasn't in our video, further making us look bad/dishonest. I'm not entirely sure what was to gain from that...
Monthly train passes are expensive. Not TransUnion's fault, but there was a $200+/month fee to basically work in Chicago itself. Keep that expense in mind if you have to commute from places like Naperville/Geneva.
There aren't many positions for Interns to transition into unless you're in the right place at the right time. It's hard to estimate, but I'd say there was about one permanent role out of every seven interns. If you need experience, it's a good place to spend a summer. If you need a post-graduation job, look elsewhere.
