> Rails/Django are fast enough for almost all apps...
Absolutely not true for Rails. In an Elixir app with Phoenix my response times are anywhere from 0.2 to 12 ms while the Rails app that uses the same database has response times anywhere from 300 to 2000 ms.
(Before you ask, I did went the extra mile to rewrite one of the small Ruby on Rails apps from my job to Elixir & Phoenix and maintain it as a feature-complete clone, just so I can have objective data.)
If we compare web app stacks, Elixir & Phoenix app is orders of magnitude faster than Rails in particular and this is not an exaggeration -- can't talk for vanilla Ruby though, I've had positive experiences with mid-sized Sinatra apps; but they still weren't capable of more than 20-30 requests/sec if you are looking for consistent throughput.
I truly like Go but to me it has always been a much better choice for highly performant microservices. I tried 3 separate web frameworks 12-16 months ago and I simply concluded Go isn't a good fit for a full web app -- at least compared to the conveniences and dozens of other advantages of an Elixir & Phoenix app. Go is definitely better in several other areas.
TL;DR -- Rails is very far from "fast enough". It's very okay for internal apps used only in business teams where the load won't ever be more than 20 requests a minute.
Absolutely not true for Rails. In an Elixir app with Phoenix my response times are anywhere from 0.2 to 12 ms while the Rails app that uses the same database has response times anywhere from 300 to 2000 ms.
(Before you ask, I did went the extra mile to rewrite one of the small Ruby on Rails apps from my job to Elixir & Phoenix and maintain it as a feature-complete clone, just so I can have objective data.)
If we compare web app stacks, Elixir & Phoenix app is orders of magnitude faster than Rails in particular and this is not an exaggeration -- can't talk for vanilla Ruby though, I've had positive experiences with mid-sized Sinatra apps; but they still weren't capable of more than 20-30 requests/sec if you are looking for consistent throughput.
I truly like Go but to me it has always been a much better choice for highly performant microservices. I tried 3 separate web frameworks 12-16 months ago and I simply concluded Go isn't a good fit for a full web app -- at least compared to the conveniences and dozens of other advantages of an Elixir & Phoenix app. Go is definitely better in several other areas.
TL;DR -- Rails is very far from "fast enough". It's very okay for internal apps used only in business teams where the load won't ever be more than 20 requests a minute.