Is Rails fast enough?
When a new language or web framework pops up, what do you usually see along with it?
Benchmarks. Benchmarks like these.
As a Rails developer, you might be embarassed to see this. I mean, Rails is more than a full order of magnitude slower than Phoenix! And even Sinatra is about 3x faster.
But what do you do about stats like this? Do you shift to another language, so you can get faster response times? Do you move to a different architecture, with some services written in Go, some in Elixir, talking to a frontend in JavaScript? What would you even use Rails for, then?