What is the ruling on working for government sovereign wealth funds that invest in usurious companies and banks around the world, knowing that the purpose of the work is to serve the nation and gain international experience?

There is no harm in working with investment funds if their activity is permissible and one can limit oneself to it. However, if it is not possible to limit oneself to the permissible and these funds deal with usury (riba), then it is not permissible to work with them. Allah has threatened those who consume usury with war, saying: "O you who have believed, fear Allah and give up what remains [due to you] of usury, if you should be believers. And if you do not, then be informed of a war [against you] from Allah and His Messenger. But if you repent, you may have your principal – [thus] you do no wrong, nor are you wronged." (Quran 2:278-279). Furthermore, the Messenger of Allah, peace and blessings be upon him, cursed the consumer of usury, its payer, its scribe, and its two witnesses. Serving the nation and gaining experience do not justify engaging in forbidden work. One must abandon dealings with forbidden matters because nothing equals safety in religion.