Comment by hardolaf

I started off programming doing web development working on an community run asynchronous game where we needed to optimize everything to run in minimal time and power to save on cost and annoyance. It was a great project to work on as a high schooler.

Then in college, I studied ECE and worked in a physics lab where everything needed to run fast enough to read out ADCs as quickly as allowed by the datasheet.

Then I moved to defense doing FPGA and SW work (and I moonlighted in another group consulting internally on verifcation for ASICs). Again, everything was tightly controlled. On a PCI-e transfer, we were allowed 5 us of maximum overhead. The rest of the time could only be used for streaming data to and from a device. So if you needed to do computation with the data, you needed to do it in flight and every data structure had to be perfectly optimized. Weirdly, once you have data structures that are optimized for your hardware, the algorithms kind of just fall into place. After that, I worked on sensor fusion and video applications for about a year where our data rates for a single card were measured in TB/s. Needless to say, efficiency was the name of the game.

After that, I moved to HFT. And weirdly, outside of the critical tick-to-trade path or microwave stuff, this industry has a lot less care around tight latencies and has crazy low data rates compared to what I'm used to working with.

So when I go look at software and stuff is slow, I'm just suffering because I know all of this can be done faster and more efficiently (I once shaved 99.5% of the run time off of a person's code with better data packing to align to cache lines, better addressing to minimize page thrashing, and automated loop unrolling into threads all in about 1 day of work). Software developers seriously need to learn to optimize proactively... or just write less shitty code to begin with.