It seems that everyone in web is just blindly following whatever flavor of the month tech stack tech bloggers who probably spend more time writing about software than they do writing software are hyping. CRUD apps(IE 90% of web based companies) are probably one of the most solved problems in tech. Why is it that every week there is some post by some inane startup nobody has ever heard of about "why we rewrote our stack from Ruby/Python to X shiny new language that people use buzzwords I probably don't even know the meaning of to describe"? This sort of lines up with that post from yesterday I think about companies just wanting to push out the product as fast as possible rather than caring about the actual quality of it. Why wait until you need to scale and hire 10 100k/year engineers to rewrite your app into a capable language and migrate it with 0 downtime instead of just doing shit right the first time? Seems like it would be a lot less headache, even if VCs were throwing piles of cash at you. Snapchat, for whatever other things you can fault them technically for like being hacked or whatever, did this right. They built on Java and deployed to App Engine and their application scaled right up.
I can understand extreme cases like Twitter(went from Ruby/Rails to Scala), where it was essentially a trivial CRUD application that eventually got so enormous that language performance features became an issue.
Also I don't understand why web people are so obsessed with "concurrency". How does concurrency help webapps that are just getting a request, doing some stuff with databases(which have their own well implemented concurrency mechanisms) and sending a response back so some tween can look at pics of their friends and send gossipy messages? Unless you are doing something that requires long running processes like video streaming or an online MMO type game, what is the point of it? Oddly the the parent posts' link's application in question is some kind of server monitoring service, so I really don't know why they chose Ruby.