What is the ruling on working as an engineer for an institution that provides long-term interest-bearing loans to citizens for home improvement, while also monitoring the use of the loan for its intended purpose?

It is not permissible to work at this institution because it is involved in Riba (usury/interest), and working there constitutes cooperation in sin and aggression. Allah Almighty says: "And do not cooperate in sin and aggression. And fear Allah; indeed, Allah is severe in penalty." (Quran 5:2). And whoever leaves something for the sake of Allah, Allah will provide for him from where he does not expect, as Allah Almighty says: "And whoever fears Allah - He will make for him a way out And will provide for him from where he does not expect." (Quran 65:2-3).