Forget business/finance. Most firms don't hire from that background, and will teach you trading fundamentals. They want people with useful skills who are bright, and expect them to pick up the domain knowledge on the job.

For strategy work, in addition to CS, study something like Math/Physics/Stats/ML. If you're more technically inclined, add EE and hardware/low-level systems design. For finding jobs and interviews, it certainly helps to attend a top-tier school (think Ivys + MIT, Stanford, Caltech, etc.).

Keep in mind the field is constantly changing and may not exist in the same way 4 years from now.

Being humble, open-minded, curious, clever and diligent will always help, too.