What is the ruling on working as a software engineer in a financial brokerage company?

The ruling on your work in this company depends on the ruling on the company's work in brokering securities. If the company deals only with companies whose activities are permissible and does not deal with usury, then your work is permissible. However, if the company deals with companies whose activities are forbidden or deals with usury, then its work and your work are then forbidden.