What is the ruling on working to develop a financial funding company that deals with interest-based systems for car financing and installment cards?

If the company sells cars it owns on installment at a higher price than the cash price, and with specific conditions, this is permissible. It is stipulated that a firm agreement be reached on the installment sale price, that interest not be mentioned independently, that no penalties be imposed for late payment, and that the company not retain ownership of the car after the sale.

However, if the company does not own the cars and uses a "installment card" system to purchase from other places, two possibilities arise: 1. The company buys the car for the customer and then sells it to them at a profit: This is permissible if the company first buys the car for itself and takes possession of it, then sells it to the customer at an agreed-upon price without imposing penalties for late payment. 2. The company pays money to the customer or pays the price on their behalf in exchange for interest: This is prohibited usurious lending, because it is a loan that brings a benefit.

Based on this, working for this company depends on the nature of its transactions; if they are permissible, then working there is permissible, otherwise it is not permissible due to its cooperation in sin.