Dr. Monzer Kahf, a prominent economist and counsellor, states the following, states the following: Our Most Beloved Prophet, Muhammad, peace and blessings be upon him, said in an authentic saying that is reported by Al-Bukhari and Muslim that “the Wrath of God is on the taker of Riba, its payer and its writer.” An authentic version of this Hadith is reported by Muslim and adds the word “and it two witnesses” Yet another version adds “and said (i.e., the Prophet) all are alike.

Therefore, the Shari’ah ruling is that it is prohibited to write a Riba transaction and be a witness to it. This is in addition to taking and giving it. A Muslim may not take a job that requires her/him to write a Riba contract or sign it or order it for a customer or for herself. 

However, this does not mean that all jobs in an organization whose main business is to make interest transactions, such as a bank, are not permissible in the Shari’ah (in spite of the obvious fact that all such jobs help, one way or the other, the interest-based transactions). There is no sense, and it is a kind of posing too much restrictions on people, to expand the prohibition beyond what it said in the hadith. This means that many jobs in banks and investment banks are permissible (although they are not from a Shari’ah point of view, the best jobs in the world).

Consequently, one can be an analyst, a researcher or an IT officer in an investment bank as long as you can avoid writing, signing, ordering or be a witness to an interest contract (such as sale/buy bonds for a customer).