According to Hadith, those are cursed who take interest, give it, write it, and who give witness to it. If you avoided all these things in your job then your earnings are lawful for you. And, when you are in Saudi Arabia we hope that your job is OK. But, we do not know what kind of banking system is prevalent there. However, if any question arises in your mind then better contact the local Ulama and Muftis regarding the same.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband