Is Al Rajhi Bank an Islamic bank or a usurious one?

The aforementioned bank has both interest-based and Islamic departments. If your work is in a department that deals with interest, then it is not permissible for you to work there, because it is aiding in sin. And whoever aids in a disobedience is a partner to its perpetrator in sin, due to the Almighty's saying: "And do not cooperate in sin and aggression." And due to the hadith: "The Messenger of Allah, peace and blessings be upon him, cursed the devourer of usury, its payer, its scribe, and its two witnesses, and he said: 'They are all alike.'" However, if your work is in an Islamic department that adheres to legitimate Sharia guidelines and is independent of the interest-based bank, then there is no harm in working there.