I'm interested in getting into developing trading systems, black box, HFT, etc. My primary experience is with C# and .Net (7 years). I've also done some sockets programming. I have some experience in finance working on analysis applications (2 years). My goal is to move into developing automated trading systems for a hedge fund, bank, etc.

Is there any way to learn the skills needed for this without somehow getting the job first? I've looked at the open source tradelink, IB interactive brokerage, etc. I'm playing around with this framework, and may hook it up and do some paper trading. However, I'm not sure if this has much relationship with how a well-funded entity would be conducting a high-level automated trading operation. I.e. would the tools and frameworks they prefer be a totally different skill-set? Also wondering if I need to learn C++ and/or Java for these types of apps.