I am in a position where I need to decide on a job offer I recently got. It’s a role of a Software Engineer at a company making financial service software. The majority of the clients of the company are Investment Banks (not conventional or retail banks) and some of the clients are trading companies and brokers. They are hiring me for the job of developing software to facilitate post-trade processing (software that can settle transactions, generate accounting reports etc.) for such clients. Now, these Investment banks are usually also involved in non-sariah-based transactions.
So I wanted to know will this nature of the job and the salary received by the company be considered Halal or not.