For the moment I get a 2% monthly profit for a USD 2,000 exposure. It means that I make about USD 40 per month... Nothing too crazy and I don't know how long it will last.

If I want to invest more money I will need to develop a mechanism to check that there is enough liquidity for my limit orders to be executed before they are sent. I am working on a mechanism that reads the order books of the two involved exchanges. If and only if there is enough liquidity on both exchanges then the trades are generated.

But more that than I like the challenge of building automatic systems. I like to see my system live, sending orders automatically. But I want to improve it (new exchange connections, order books analysis, failover, etc) and I'm not a professional C++ developer. My goal is to find C++ guys that would be interested in contributing. Also, the system is pretty fast and securely connected to Bitcoin exchanges using C++ libraries and in the future I hope to make it a good example for the open source community (not really the case right now...  ).