I do it to trade options successfully. I use technical analysis and it's definitely possible. It's not a side project, it's my income.
I only use PHP although the cool thing now is Python and has built in libraries. I don't need near instant execution and I started a long long time ago so rewriting everything is not something I want to undertake.
I use minute based data with all sorts of different indicators based on the stock, it's market, and competitors.
It's not something I think you can do as a side project as you have to refine it each day, I think if you aren't spending 8 hours a day looking at charts it will be hard to adapt/evolve.
Current stance is the market is bullish. I was bullish in December also.
