Quote from TSGannGalt:
In terms of programming you pretty much have only 3 choices:
C++
Java
C#
Reason is quite obvious... testing engine is not the only thing you'll be required to program. Whatever language you pick, you will definitely need to know C++ so that you can tweak lib codes. For example, QuantLib, QuickFIX, Apache, etc. etc.
I personally use C# and it's my primary language. 80% of my codes are in it. But the core engine whether it be my FIX engine / Lib or my Grid Computing Lib is written in C++ which is wrapped to my C# needs. No matter how hard you try, most people end up having a setup like any institutional model with:
Core - C++
Middleware - .NET / Java (Depends on what OS the Core Server is)
Front End - Anything you like (C# for me)
Other than that...
I would try to get out of the retail environment ASAP. Try talking to a prop. firm or a clearing firm and work out a deal to gain as much access close to what you get at an IB. I actually have a prop. firm clearing my trades for BATS (I have a direct connection with BATS, and when I send my orders, BATS drops the order msg. to the prop. firm). They actually get a pinch of the rebate from my trading just for clearing my trades. No extra fees.
It's a pain in the arse, when you start because you don't have a track record. You can't be greedy, you need to suck it up and invest / sacrifice a lot, to build your capital and reputation. When I started (in Chicago), I was walking into offices with my model looking for seed capital... and one firm started me off with a 1 lot / and 20% pay out (plus disclosing the source). That eventually grew and in 2 years, I ended up with 80+% payout with full control over the invested capital and source logic (rather than the firm setting a lot size).
The firm who "cheated" me with a 1 lot / 20% in particular, introduced me to several hedge funds in the area (pretty big ones) for me to develop models. I met people and .I learned / stole how the big boyz traded and developed. So there are alot of sacrifices but provided that you see the whole picture, it's worth it.
Finally....
Being an independent automated trader is going to be tougher than your average IB job. 3-4 years into your new job, you'll find yourself appreciating all the support you got from your colleagues within / out of your team.
You know who you're competing against. Can you take "them" on, on your own?