Assalaamu alaykum. I work as a software engineer in a company and am responsible for maintaining the online-shop. We offer a variety of payment methods, including instalment financing over banks. We are not making a contract, my job was to put a button in the payment methods area that directs the customer to the contract and also transfers personal data (like the name and the street) to the contract, which is not locked in any way but can be changed by the customer. It is mentioned in a hadith that the Prophet, Sallalahu aleyhi we selem, said that the one who takes usury, the one who gives it, the one who writes it down, and the one who witnesses it are all the same. So do I, as the maintainer of the website, fall in any of these categories? I want to go to university in 12 months. So if it is prohibited that I work in this company, then can I stay there until I start going to school?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger.

If the button that you are developing directs the customer to his contract with the company and not to a usurious contract, regardless of the payment method, be it in cash or a usury-free loan, then there is no harm for you to develop such a button. But if this button directs the customer to the bank or a usurious contract, then it is impermissible for you to partake in this transaction even by merely developing such a button directing the customer to the bank or a usurious contract, whether this contract is initial or final. If you take part in this transaction, then you join in bearing the sin of taking a usurious loan. It is also feared that you may be included in the relative curse promised to the one who writes a usurious contract.

As for your question whether it is permissible for you to retain your job or not, if your job is not confined to devolving prohibited programs and you do other lawful work duties, then it is permissible for you to retain your job, carrying out the lawful work duties only. Please refer to fataawa 83019 and 100314 about the prohibition of partaking in any usurious transaction, underlining that rule concerning the means to achieve something is the same as the one concerning the objectives in that thing.

Allaah knows best.