"HFT" means different things to different people.

I've worked at places where ~5us was considered the fast path and tails were acceptable.

In my current role it's less than a microsecond packet in, packet out (excluding time to cross the bus to the NIC).

But arguably it's not true HFT today unless you're using FPGA or ASIC somewhere in your stack.

The one person who understands HFT yeah. "True" HFT is FPGA now and also those trades are basically dead because nobody has such stupid order execution anymore, either via getting better themselves or by using former HFTs (Virtu) new order execution services.

So yeah there's really no HFT anymore, it's just order execution, and some algo trades want more or less latency which merits varying levels of technical squeezing latency out of systems.

Software HFT? I see people call Python code HFT sometimes so I understand what you mean. It's more in-line with low latency trading than today's true HFT.

I don't work for a firm so don't get to play with FPGAs. I'm also not co-located in an exchange and using microwave towers for networking. I might never even have access to kernel networking bypass hardware (still hopeful about this one). Hardware optimization in my case will likely top out at CPU isolation for the hot path thread and a hosting provider in close proximity to the exchanges.

The real goal is a combination of eliminating as much slippage as possible, making some lower timeframe strategies possible and also having best class back testing performance for parameter grid searching and strategy discovery. I expect to sit between industry leading firms and typical retail systematic traders.