I have a lot of experience with Brazil.
I will give you an example that comes to mind: ecommerce is still behind in Brazil because you have such a lack of trust and crime and bad infrastructure. If I were to invest in Brazilian ecommerce, you already have MercadoLivre and Magalu and Americanas, but I would try to create a service that creates a cheap, reliable address for people to ship their Ecommerce to. Like one in every block in Sao Paulo. I'm just spitballing here, but my point is this: you know Brazil better than most people. Look up something other countries have, think about why Brazil does not have that, and then try to overcome the challenges that Brazilians face.
Or you can just find other markets, Brazil is a pain in the ass to do business in.