Does anyone here have a trading strategy where they look at functionality or the development team behind the coin?
That is called fundamentals. You look at the fundaments of the coin similar to how they do it for stocks. An investor studies the development behind the coin and they invest on it if they see a good development to it. It is a good strategy for the long term since you are looking at it in the long run for your investment. Investing in something good that would last is a good investment.