I applied for the internship on the CSX website and on my university career site. I met two different recruiters at events at my university. I was emailed with an interview offer that week. I did a one on one interview with one of the higher up finance managers. Currently still waiting to hear back from the company. It wasn't too difficult. Mostly behavioral questions.

Timed finance assessment first (basic balance sheet/time value of money questions), then short phone interview if you pass. There was a dinner the night before the actual interviews with the other candidates and two employees. It was very relaxed and the restaurant was quite nice. The next day there were two 1:1 interviews and a case study presentation. After that, you are taken to lunch with another set of two employees. You and the other candidates rotate throughout the day doing your interviews/presentations and get to talk a lot in-between. The whole experience was so laid-back and there are endless opportunities to talk to plenty of employees. They've been using the same case study for years, and it's just important to realize that they aren't necessarily paying attention to the exact numbers you get, it's more of how you present the information that counts. The interviews were relaxed and just went over your resume and experience-related questions (Pro tip: drink as much water as you can between each activity). Offer came 4 days later. It's a great company, and I was so anxious when I didn't need to be. They really make you feel at home!