What is the ruling on working for a company that electronically connects sellers and buyers, where transactions are mostly conducted through usurious banks, and is the company's commission for these services considered aiding usurious banks?

The fact that the buyer or seller will deal with an interest-based bank account does not prohibit the transaction or mediation thereof. What is prohibited is dealing with someone who will enter into a forbidden contract because of that dealing. Opening accounts in interest-based banks is considered assisting them, and scholars have issued fatwas regarding its prohibition for those who can find an Islamic alternative. However, dealing with these accounts and receiving or depositing the price through them is something that has become widespread and difficult to avoid. "Hardship brings ease," and "when a matter becomes narrow, it expands."