What did you have when you were at Carnegie Mellon if I may ask!
1. programming [A]
2. algorithms
3. operating systems
4. compiler design
If you were lucky like me, and a graduating student bestowed upon you a coveted key to the graduate terminal room, then you could hack on those excellent DEC VT-100 terminals besides James Gosling, and buy bottles of Coke from what was perhaps the first vending machine connected to the internet.
[A] Interesting in that it was a school-wide class that you were required to take and to pass. Programing was done in Pascal on a mini-computer-based IDE.
You may be interested to know that (1) is still required, even for CFA people