RailsConf 2016 - Rails to Phoenix by Brian Cardarella

I can't speak about experiences with Ruby/Rails since I don't use that stack but I can give you advice about both Scala and Elixir. I used to be a Java programmer and fell in love with Scala and functional programming. Scala helped me do things that I couldn't do so easily in Java in a more explicit way. However, I found doing web development with Scala to be more cumbersome than helpful but was still a great learning experience for FP in general. Since late 2015, I've been all-in on Elixir. Elixir does everything I wanted to Scala, specifically pattern matching everywhere and how powerful it is. Since Elixir uses BEAM, it's incredibly lightweight but can scale without any configuration. The community around Elixir is fantastic and helpful and everyone is growing together. Brian Cardarella (well known in the Elixir community) gave a conference talk at Rails Conf about switching from Rails to Phoenix (Elixir's goto for web) and that may be a good start to empower you to make a decision: [this video] . A great resource for learning Elixir if you choose that route is Programming Elixir 1.2 by Dave Thomas. It's a great book for beginners and can help with you understand Elixir semantics and functional programming.

> but Erlang/beam code is not that fast. True, no doubt. You wanted a comparison why phoenix is faster than rails. And simply doing things at compile time reduces work at runtime. In Ruby, all Metaprogramming must be done at runtime, for example via method_missing trickery (been there, done that). > Ruby's templates are parsed into code that stays in memory, too, so it's not like they're re-parsed each and every time. This is actually not the same. A single immutable blob of binary (elixir strings) which is shared throughout the whole application can leverage hardware caching better. Jose could answer this probably better than I can do. > someone should dissect these things in a real-world-ish application to see what's actually true. Moz.com recently had fun with Elixir [1]. You may also have a look at [this video] from latest RailsConf. > The claim was 'fast' though Well at least I know that BEAM processes are far lighter than eg: goroutines. Also there is a per-process GC, so no "stop the world", much smaller units for individual collects, and when a process finishes before the heap grows full, it can be discarded directly. > maintainable, which seems curious given that there are no really old Phoenix apps out there Fair enough. Personally I'd not wait until a software stack is a decade old before even considering it. I have at least worked on Elixir/Phoenix projects for many months now on-off with multiple colleagues, and it was/is still pure joy. Aesthetically pleasing syntax