A lot of the comments here seem to be missing something quite important: Scala and Go are not similar languages.
Scala is a large and complex language, encompassing multiple programming idioms. Teams programming Scala (as with C++ and many other "large" languages) often have difficulties nailing down what portion of the language they are going to use. "Java-without-semicolons" all the way through to idiomatic, functional Scala.
Go is a relatively small, simple language. You could easily learn Go's basic syntax and semantics in an afternoon or two. Simplicity and suitability for programmers is an explicit design goal.
Switching away from Scala due to lack of experience while simultaneously picking up Go is not as illogical as everyone seems to be implying.
That seems weird to me:
* No one having a deep knowledge of Scala is mentioned as a problem,
but they will learn Go.
* They rule out a language because of its syntax.On the github page it says the router sits between nginx and varnish and does:
* Reverse proxy, forwarding requests to and serving responses from multiple backend servers on a single domain.
* Redirector, serving HTTP 301 and 302 redirects to new URLs.
* Gone responder, serving HTTP 410 responses for resources that used to but no longer exist.
Something is wrong with this statement:
"Scala is great for performance, but quite bad at resource usage"
"No-one in the core GOV.UK team had a deep knowledge of Scala, and particularly how the old router worked"
So they are ditching Scala, because no one in the team is an expert, while replacing by a language that everyone has to learn?!?
As they are Using Nginx already interested to know if they ruled out openresty or did not consider it.
"Erlang, Go, Scala, and Clojure are all good fits and represent the current state of the art." - why is the choice so limited? It seems to be quite JVM-focused as well, I would consider F#/Nemerle as well. Erlang was invented in 1986 by the way - so a safe bet rather than "state of the art".
Not impressed.
I have nothing against Go (in fact I like it) but they seem to have built GOV.UK with every damn bit of technology there is available. I've seen Varnish, Go, Ruby, Python, Scala, Java, Mongo, MySQL, nginx, rails, sinatra, Django and PILES of Not Invented Here.
Also I'm not sure it's a great use of public money to build stuff like this when they should have nginx/apache up front and some configuration.
In fact this whole thing stinks of crappy information architecture resulting in a massive front end router hack that they did in Scala, binned and moved to Varnish, then binned and moved to Go.
This is not one "cohesive" web front end. It's a rat's nest and an increasingly expensive one.