Ruling on making programs that banks can use in giving riba-based loans

If this program can be used by the riba-based banks to get
information about those to whom they are going to give riba-based loans,
then it is not permissible to sell it to them, or to work on it, because
that is helping in sin and transgression, and Allaah, may He be exalted,
says (interpretation of the meaning):

“Help you one another in Al‑Birr and At‑Taqwa (virtue,
righteousness and piety); but do not help one another in sin and
transgression. And fear Allaah. Verily, Allaah is Severe in punishment”

[al-Maa’idah 5:2]

And the Prophet (blessings and peace of Allaah be upon him)
said: “Whoever calls to misguidance will have a burden of sin like that of
those who follow him, without that detracting from their burden in the
slightest.” Narrated by Muslim (4831). 

There is a stern warning concerning riba, and curses for
those who do it, write it down and witness it; this is a deterrent to every
wise person from getting involved in it or helping in it. 

Allaah, may He be exalted, says (interpretation of the
meaning):

“O you who believe! Fear Allaah and give up what remains
(due to you) from Ribaa (from now onward) if you are (really) believers.

279. And if you do not do it, then take a notice of war
from Allaah and His Messenger but if you repent, you shall have your capital
sums. Deal not unjustly (by asking more than your capital sums), and you
shall not be dealt with unjustly (by receiving less than your capital sums)”

[al-Baqarah 2:278-279]

and Muslim (1598) narrated that Jaabir (may Allaah be pleased
with him) said: The Messenger of Allaah (blessings and peace of Allaah be
upon him) cursed the one who consumes riba and the one who pays it, the one
who writes it down and the two who witness it, and he said: they are all the
same. 

So beware lest you be helping in this grave sin. 

We ask Allaah to protect you against that and to make it easy
for you to find halaal and blessed ways of earning a living. 

And Allaah knows best.