As far as Islam is concerned, it is permissible for a Muslim to work in any department in a conventional bank as long as he does not prepare any interest-based contracts or sign them on behalf of the bank.
On this issue, Dr. Monzer Kahf, a Scholar in Islamic Economics and a Financial Expert, stated,
“Working in a bank is permissible provided that one does not handle interest loans or any other prohibition. Nowadays, if the objective is learning and gaining experience, there are many other opportunities in Islamic banks and similar institutions to do that.”
Dr. Monzer also said while responding to a a question related to this issue;
“It is permissible to work in any department in a conventional bank, credit department, the IT or software department or others, as long as you do not prepare any interest-based contracts or sign them on behalf of the bank.
This is the opinion of the greatest Sharia scholars of our time such as; the late Sheikh Mustafa Al-Zarqa (died 1999), Sheikh Al-Qaradawi, Sheikh As-Salami of Tunisia and Sheikh Adh-Dhareer of Sudan.
The argument is that such jobs in conventional banks are not included in the wrath of Allah that is mentioned by the Prophet (peace and blessings be upon him) on the giver of riba (interest), its taker, its writer and its two witnesses (reported by Muslim). Besides, a prohibition of working in banks places unnecessary inconvenience and hardship on Muslims both in the Muslim majority countries and Muslim communities of other countries.”