It is not permissible to work in riba-based banks at all because that involves consuming riba, or writing it down, or witnessing it, or helping those who do that.

If your work involves helping the company in any way with any kind of cheating or stealing, then it is not permissible. But if your work has nothing to do with the haram things, and the company also has some other departments that do not deal with haram things, then it is permissible for you to work in the departments that deal with permissible things.

It is not permissible for a Muslim to work for a company that deals in interest and other prohibited transactions. The prohibition includes all the employees who work in the company, even the doorkeepers and security guards.

Participating in pension plans other than those organized by the government is a kind of gambling. But if participation is compulsory, there is no sin on you.