Mechanical Sympathy

June 24, 2021

About half a year ago, someone sent me the article Mechanical Sympathy: Understanding the Hardware Makes You a Better Developer. It’s worth a read. At the time, it irked me because in the context at that moment, it felt like advocacy towards premature optimization.

Fast forward to now. I’m working on a hobby project using C, since I haven’t really had a chance to write C in like 15 years. It’s refreshing to have to think about memory layout and allocations for everything you do. The lack of garbage collection helps prevent convenient abstractions that come at a high performance cost. C also doesn’t provide programming abstractions that hide what code is going to run–what you see is what you get.

It’s hard to find people that are passionate about writing software. A lot of people want to ship things and move on. If there aren’t enough tests, the code’s lifespan is decreased as it will be much more difficult to refactor. Likewise, if the code isn’t performant or correct, it’s also likely to be replaced. If you manage to have correct, performant, and well tested code, then you have a gem.

It’s even harder to find people that benchmark their code. I think it’s one of those things–if it needs to be optimized, someone will look at it. But in my experience, that threshold is high enough that it rarely occurs. Since it rarely occurs, people will often do a poor job at it–commonly by making guesses at why things are slow (without profiling) and not benchmarking the changes they make.