A:
It is not permissible for a Muslim to work in a bank that deals with Riba, even if the job that they are appointed to do is not related to the Riba-based dealings. This is because they would be assisting those who work with Riba and cooperating with them. Allah (Exalted be He) says:
...but do not help one another in sin and transgression.
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.