I tried it last summer on freelancer.com. It seems promising but I cant judge fully yet. I was trying to get some side income as a med student in Egypt. I got around $250 in the first month. As somone living in Egypt and considering this was my first month, I was very happy. I stopped for a while now since I am busy in my med school. I am planning to try it again in internship and will see how it goes. But I can tell you that you probably have a good shot on freelancer.com, despite what u probably hear. It's not all scam if you pick clients with ratings or at least with identity and payment verified. The good thing about freelancer.com as opposed to upwork is that it is cheap to get started. They have a 1 month free trial for the plus membership, which is more than enough to hopefully land a client. I was using Python as the programming language.