Ref. No. 1314/42-684
In the name of Allah the most Gracious the most Merciful
The answer to your question is as follows:
The bank job in which one has to write interest based accounting is illegal because such bank job is a kind of cooperation in interest business while the Holy Qur'an has encouraged to help in good deeds and clearly discouraged to help in evil deeds. There is a clear warning in Holy Hadith for such people: Hazrat Jabir (ra) narrates that the Prophet of Allah (saws) cursed the receiver and the payer of interest, the one who records it and the two witnesses to the transaction and said: They are all alike in guilt (Sahih Muslim).
Therefore, adopting bank job is not permissible. You have to look for another job. If you are already working in a bank, you may continue your current job and keep looking for another halal one at your level best.
وتعاونوا علی البر والتقوی ولاتعاونوا علی الاثم والعدوان، واتقوا اللہ ان اللہ شدید العقاب (القرآن، سورۃ المائدۃ 2) "عن جابر قال: لعن رسول اﷲﷺآکل الربا، وموکله، وکاتبه، وشاهدیه، وقال: هم سواء". (الصحيح لمسلم، با ب لعن آکل الربا، ومؤکله 2/27)
And Allah knows best
Darul Uloom Waqf Deoband