I'd add that if you are truly interested in HFT the time when you could make C/C++ software fast enough is either gone or very short lived. Much more valuable would be FPGA programming or other similar skills.
For a layman, Can you please explain why FPGA skills are good to have? Some years, I could understand that processors were not fast enough so FPGA parallelism was useful...I think modern processors have caught up.
FPGA cards are the easiest/cheapest way to get programs into the chip level. You can bypass OS level operations, memory/cache operations etc.
That said, you probably could build bespoke machines out of modern processors that perform better (and someone might be doing this), but it would be very expensive. FPGA's offer a middle ground between that and software.
