Not just me. With the explosion of quantitative and algorithmic trading, this would be cutting edge. The execution part of it would be the major hurdle.
Weird/backward question imho. I believe you start with an idea/inspiration and then implement it. Many people use multiple platforms for different strategies/purposes. I may use one for charting, one for low commission execution, one for low latency execution, one for backtesting, one for some freebies you will not get elsewhere, etc. What is it you are trying to achieve? If I was approached by guys from Robinhood, it would take them 10 seconds to convey their vision. Vision inspires people to build great products, not the other way around.
You will need an expert coder, trader, systems analyst, database analyst / modeler / architect, unix or windows administrator / developer, java or c# programmer, technical analyst, fundamental analyst, quant, systems architect, standards, UI analyst, web analyst, systems integrator etc. How many skill sets do you have certification and considered an expert by industry peers? The whole thread reminds me of a management change that can't figure out a legacy system that have been working fine for years and attempts to rewrite it without all the specifications and proper due diligence. And blows the budget by over 500%, then scraping the project due to incompetence. In summary, you guys start programming and i'll go get the specs...
I'm interested in a backtesting + live systematic trading platform. I've used backtrader, but to be honest, I would prefer something in C++. My plan was that once my trading covered my living expenses (hahahahaha), I would write a C++-based backtesting + live trading platform.
Hummm... this is a very crowded space. That would be a good idea if we were 25 years ago, but in 2018! I wish you good luck.