I doubt I will forget the time I first booted up an Elixir Phoenix server and got something like `[info] Sent 200 in 409µs` and stared at that `µs` for a while before it dawned on my that that was the symbol for microseconds.
I was so used to 20-40ms that I couldn't even comprehend that it could be 80x faster. A year later since playing around in Elixir's world, and I'm still just so impressed by its speeds.
Recently I started writing a bunch of tests for a Phoenix application for my first Phoenix app.
After a day of hacking around and learning as I go I had 63 tests of which 57 of them are full blown controller tests where a good amount of those tests are dealing with a "current user" and reading / writing things from a database. I'm even using a "Faker" library to generate fake data for all of the DB attributes.
The entire test suite runs in 600ms. That's 600ms for ~60 controller tests from start to finish. That's in a worst case scenario too where the code is on a non-SSD and that code is volume mounted into a Docker container on Windows while I use WSL.
Sometimes things work so fast that I'm actually worried it's not doing what I think it's doing, but then I run --cover and see that I have 95%+ test coverage on the things I care about, so that code is getting reached.
I was so used to 20-40ms that I couldn't even comprehend that it could be 80x faster. A year later since playing around in Elixir's world, and I'm still just so impressed by its speeds.