[jasonpass]

I agree with the "don't drink too much kool-aid" but you can also completely develop and deploy Phoenix without worrying about distributed systems, umbrella-refactorings, and so on. At least, I have. :)

This has been the whole appeal behind Phoenix: it truly is as productive as Rails/Django but much more performant. Better throughput, faster boot times, faster tests, etc. Fault-tolerance, channels and presence are the cherry on top.

I have seen Chris keynote about the presence implementation and they seem to have used really advanced techniques that I cannot not quite follow. Still, this week we are going to deploy presence into production and all we really care is that it just works (and without Redis or any other dependency).

[davidw]

> it truly is as productive as Rails/Django but much more performant

I'd be a little bit skeptical of both things: Rails has a huge, mature ecosystem, and Erlang is often faster than Ruby, but is not a "fast" language.

http://benchmarksgame.alioth.debian.org/u64q/compare.php?lan...

Where Erlang really shines is that it's running in a single Unix process, yet can handle multiple things going on at once thanks to its scheduler (and not have ugly code, because it's the scheduler doing the work, not the programmer writing spaghetti). This means that generally, it's going to handle more connections better and degrade more gracefully. This is a huge win for web sockets where you have a connection sitting open and not tying up a huge Rails process. Although even there, I guess the Rails guys are working on some new stuff that should help alleviate that problem.

Erlang is cool stuff, and well worth a look. I certainly enjoy working with it. But be wary of throwing out Rails because "new! shiny!"

[edpass]

Jason's coworker here.

The Erlang benefits you have mentioned above also fully apply to regular web requests and applications. One of Ruby biggest flaws (and consequently Rails') is poor support for concurrency. And Phoenix performs well on all aspects Jason mentioned because running tests, serving data, etc is all done concurrently.

I was also skeptical at first. I've heard talks and benchmarks reporting Phoenix is from 10x to 20x faster than Rails (like this one: https://gist.github.com/omnibs/e5e72b31e6bd25caf39a). After porting our authentication service to Phoenix (our first), we saw similar gains with less CPU and memory usage (as well as better response time averages and 99 percentiles). Our deployment infrastructure for this service is now one fourth of what it was originally.

Other than that, Rails definitely has a huge ecosystem and that should be taken into account by those planning to move to Phoenix. Honestly, it has not impacted us in any significant way but YMMV.