Is it permissible to continue working for a software company that facilitates usurious transactions through one of its programs, especially after the engineer refused to carry out the usurious part and the company offered to have someone else do it, or if another branch of the company is opened for this purpose? And what are the regulations for continuing in this situation?

Usury is one of the gravest sins. It is not permissible to work in programs that assist usurious banks, nor is it permissible to approve of another person performing these forbidden acts. The company owners must be advised to avoid working in programs that aid in usury. If they do not respond, you will have fulfilled the duty of advising.

If possible, move to a job free from these evil acts; otherwise, there is no harm in staying while striving to reform the workplace.