Is it permissible to work in providing consultations or implementing technical projects for banks, knowing that the nature of the work involves dealing with other entities such as telecommunications and government sectors?

A Muslim should be a helper in righteousness and piety, and an impregnable barrier against sin and transgression. One should not be a bridge for sin to cross. Providing services and consultations to public entities is permissible unless it pertains to something forbidden. As for usurious banks, it is not permissible to cooperate with them or provide them with consultations, because that entails assisting in usury. The Prophet, peace and blessings be upon him, cursed the one who consumes usury, the one who feeds it, its scribe, and its two witnesses, and they are all equal in sin. Therefore, if the company you work for has permissible activities and other forbidden ones, it is permissible to work for it on condition that you avoid participating in or assisting with the forbidden activities, and refrain from directly engaging in transactions or consultations specific to usurious banks.