Some of the big performance wins don’t come from the raw compute speed of Erlang/Elixir.
Phoenix has significantly faster templates than Rails by compiling templates and leveraging Erlang's IO Lists. So you will basically never think about caching a template in Phoenix.
Most of the Phoenix “magic” is just code/configuration in your app and gets resolved at compile time, unlike Rails with layers and layers of objects to resolve at every call.
Generally Phoenix requires way less RAM than Rails and can serve like orders of magnitude more users on the same hardware compared to rails.
The core Elixir and Phoenix libraries are polished and quite good, but the ecosystem overall is pretty far behind Rails in terms of maturity. It’s manageable but you’ll end up doing more things yourself. For things like API wrappers that can actually be an advantage but others it’s just annoying.
ASP.NET and Springboot seem to only have theoretical performance, I’m not sure I’ve ever seen it in practice. Rust and Go are better contenders IMO.
My general experience is Phoenix is way faster than Rails and most similar backends and has good to great developer experience. (But not quite excellent yet)
Go might be another option worth considering if you’re open to Java and C#
Thank you, I really, really appreciate the thoughtful answer.
I've written APIs in Rust, they were performant but the dev experience is needlessly painful, even after years of experience using the language. I'm now using Rails for a major user-facing project, and while the dev experience is all sunshine and flowers, I can't shake the feeling that every line I write is instant tech debt. Refactoring the simplest Rails-favoured Ruby code is a thousand times more painful than refactoring even the most sophisticated system in Rust. I yearn for some kind of sensible mid-point.
Elixir seems extremely neat, but I've been blocked from seriously exploring it by (a) a sense that it may not be more any more performant than Ruby, so why give up the convenience of the latter, and (b) not having seen any obvious improvement on Ruby's hostility to gradual typing / overuse of runtime metaprogramming, which is by far my biggest pain point. I'm chuffed to hear that the performance is indeed better, that the magic in Phoenix happens at compile time, and that gradual types are being taken seriously by the language leadership.
Phoenix has significantly faster templates than Rails by compiling templates and leveraging Erlang's IO Lists. So you will basically never think about caching a template in Phoenix.
Most of the Phoenix “magic” is just code/configuration in your app and gets resolved at compile time, unlike Rails with layers and layers of objects to resolve at every call.
Generally Phoenix requires way less RAM than Rails and can serve like orders of magnitude more users on the same hardware compared to rails.
The core Elixir and Phoenix libraries are polished and quite good, but the ecosystem overall is pretty far behind Rails in terms of maturity. It’s manageable but you’ll end up doing more things yourself. For things like API wrappers that can actually be an advantage but others it’s just annoying.
ASP.NET and Springboot seem to only have theoretical performance, I’m not sure I’ve ever seen it in practice. Rust and Go are better contenders IMO.
My general experience is Phoenix is way faster than Rails and most similar backends and has good to great developer experience. (But not quite excellent yet)
Go might be another option worth considering if you’re open to Java and C#