[kazinator]

A week or two before starting, find out whom you will be reporting to. Get in touch with that person and ask about what kind of tasks they have in mind for you and whether it would be useful to prepare in any way.

Other than that, I wouldn't do anything.

Algorithms and CS stuff: you might not ever see it again.

If you study four algorithms, but you are asked to work on a fifth one that is completely unrelated, that is of no use. In development, you brush the dust off the specific algorithm or theory that is needed for a task, when that time comes.