We are living in a world that is not 100% sharia-compliant. Therefore, in my opinion, it is impossible not to touch any interest related especially in finance.
After doing some research, I found that work in a conventional bank is not allowed due to the bank profit mostly come from interest. For example, in a state-owned bank in Indonesia, 73.78% of its profit is from interest (I read their financial report).
However, how about working in a securities (stockbroker and investment bank), is it allowed to work there as a software engineer? From their financial report, 44.8% of their revenue is from brokerage revenue, 44.19% from dividend and interest income, and 11.01% is from underwriting fees. As you can see, the profit coming from an interest in securities is not as dominant as in a conventional bank.