I don’t disagree but I think people fear this more than they should. I’ve worked for financiers a few times and yeah, there you should be afraid of lag spikes going to 10 milliseconds; something most apps wouldn’t even notice.
Everywhere else I ever worked though? Meh. Nobody bats an eye if 1 out of 20 requests takes 3 seconds even. Nobody cares. And to this day Rails developers insist that ActiveRecord (the ORM of Rails) being responsible for 100-150ms delay per web request (admittedly only if it has 3-10 DB queries, of course) is small and is not important. In the meantime a similar Phoenix endpoint in its entirety returns in 7ms at the most.
When it comes to such an impressively fast dynamic language environment like the BEAM VM I don’t view some minuscule delay like 2-10 more ms as consequential. Anything that helps avoid bugs, not leak people’s private data, and not lose money should be counted as a win, even if it comes at the expense of performance.
Another example: Rust’s compiler is slow but it does eliminate several entire classes of bugs by the mere virtue of your program compiling.
IMO we need more such tech in our line of work, including in the Elixir ecosystem. It’s amazing how much traffic can a mere modern i3 mini-computer with 32GB RAM and a SATA III SSD can serve; we should focus on correctness because buying 20% more hardware capacity is a rounding error in most companies.
