Maybe by organizing contests with the help of different companies who are looking for new ambitious recruitments, who want to work and develop in the IT sphere? For an example the VK Cup.

If by make money you are asking how they have enough resources to keep the site running, I think it is through sponsorship of companies, such as Telegram, and donation of time by people such as Mike. If you mean how do they make a profit, I think answer is that they do not make any profit.

They can put ads though...nothings stopping them from putting some ads on the sides...if its better for the community then i think they should do it

Because TON gives Codeforces enough money.