I am working with my partner to try to develop a program(s) that can help us to trade stocks. We have accounts with Interactive Brokers LLC, which is a stock trading brokerage. They will provide the live feed which we will need to accomplish our goals.
These base requirements should support anything else we'll need to do in the future.
INTERACTIVE BROKERS LLC supports C#, C++, Python, VB and Java. Although any should work, and I don't believe processing speed is important because what the program will be doing will be very simple, but it what will be crucial will be the need to keep open two way communication with IB, make trade choices using current share price data and ongoing trades status and send those choices back to IB. Obviously, this speed is of paramount importance, so the choice of language now may be important in the future.
I'm not sure what all the consequences will be, but we will want the program to run in the cloud. I believe this will eliminate any speed or connectivity issues that may come from hosting it locally and give us access always. This will also mean special attention will have to be paid to security (access), but we don't have to make those exact decisions now, only to list security access in the "to do's".
We will need to trade in multiple accounts simultaniously and have normal levels of user authority for multiple users.
We will need to store (only very current data will need to be accessed for real time choices) and keep track of dozens of stocks share price ranges and volumes in 30 second intervals in spreadsheets simultaneously, perform normal spreadsheet functions automatically when conditions require and perform additional rule based choices automatically outside the scope of the spreadsheets.
I would have any potential candidates look at this list, check out IB website and give impressions of the job scope and their experience in these areas.