Agreed that they are fully aware as to who placed the order - they have all the data. However this doesn't tell them as to whether or not the trader is a HF trader. They simply classify traders into groups on the basis of their inventory half-life and inventory size. Also, given that they run slightly different strategies and aggregate the traders into groups, their inventory half-life won't be constant - hence they estimated the average half-life for each group. The average half-life for the HFT group was around 130secs from memory.
Well put. There are a million and one coders out there with the technical ability to build a high performance trading platform. A miniscule number of these coders have the market understanding required to develop a consistent method of generating alpha. Most who do are employed by banks/hedgies and wrapped up in legal straightjackets so tight they squeak when they fart. Of course, accordingly they are very handsomely recompensed. Any coder with the necessary skills who is without the knowledge required to develop a feasible strategy would be a fool not to investigate this offer further.
Though I don't have any experience with automated/algorithmic trading, I think this would be a fascinating new area to explore! I've over 7 years of experience with C#, and I've learned at least a thing or two along the way. I love to tinker with/try out various API's, frameworks, patterns, etc., and there are always several of them that I'm trying to learn and use at any given time. I'm not currently compensated for the time I spend engaged in those activities, so having a chance to try something new and interesting without compensation sounds pretty much like the status quo, eh? What would I have to lose? Now, if only I knew someone who wouldn't mind making use what assistance I might be willing to give...