A person working in a construction company that may engage in riba (usury or interest) in some of its parts; is this permissible?

The questioner : The company, this company where I am taking a contract, I am taking a bid for urban development, okay... I benefit, and he is an engineer... and we want our son-in-law to work in a trade, a craft, and so on. So I asked my son-in-law: "Do you want to do this?" He said to me: "Yes." So I spoke with the engineer; he said to me: "If he wants to be a mason, if he wants to do setting out, if he wants to do construction, I will teach him the trade he wants, meaning, he will work, he will take a wage, and he will learn a trade." I said: "Okay, where will he come?" He said to me: "He will come to me at the project." I said to him: "Where is your project?" He said to me: "My project is in the urban development, the such-and-such, yes."
My professor and I started to think; okay, they say that urban development has a connection to sins, and a connection to such-and-such, and the Shaykh, meaning, he had explained this topic to us, so we thought it was not okay... to work, but also the engineer's opinion is necessary, meaning, since he said: "Please, here is my phone, let him come down to start working tomorrow and so on," I was unable to review the matter with him. I reviewed it with him and said to him: "May Allah reward you... we were hesitant because when we heard that it was urban development, and urban development has such-and-such, and our Shaykh - may Allah reward him - had explained that, meaning, the matters are ribawi (related to usury or interest), and dealing with riba (usury or interest), and its outcome is such-and-such, and its basis is: and it is not permissible for us to cooperate; so this urban development involves assistance; because there is riba (usury or interest) in it. He said to me: "It is possible, meaning, there is a part where people buy with riba (usury or interest) and people without riba (usury or interest)." I said to him: "No problem, meaning, here is one thing and here is another, but the majority, meaning, what prevails in your suspicion is that it is riba (usury or interest)." And he said to me: "Okay, I, meaning, a company takes from a company and I build, do I have a connection or do I not have a connection?"

The Shaykh: Allah is the Greatest!

The questioner : He said: "It is not that I take the bid from this, I, meaning, am the manager of a company that takes a bid, so my Shaykh, they remain the same thing, this distance of his does not benefit us, meaning?"

The Shaykh: No, no.

The questioner : It all becomes this in one outlet, which is cooperation.

The Shaykh: Yes.

The questioner : Because there are banks and ribawi (related to usury or interest) entities, and all of it is from this!