What is the ruling on working for development funds in developing countries that contribute to non-humanitarian projects (such as tourism and hotels) and invest in both Islamic and non-Islamic banks?

There is no objection to working in funds that contribute to tourism projects or in usurious banks, as long as the worker does not directly engage in a forbidden act, such as writing down usury or accounting for it. This is because it is considered dealing with mixed wealth, which is permissible.