There are precious and free University courses for CS students
Data Science Math, Statistics, Problem Solving, Computer Architecture, Cybersecurity which are very precious for any CS student. Learning Data Science Math for free and from reputed universities.
1. Object-Oriented Data Structures in C++ By University of Illinois 2. Computer Science: Algorithms, Theory, and Machines By Princeton University 3. Cybersecurity for Everyone By University of Maryland 4. Computational Thinking for Problem Solving By University of Pennsylvania 5. Computer Architecture By Princeton University