Regarding JS slowness and not being backend worthy:
“A few details stood out after we ran the test cases and both applications passed the same functional tests. The node.js app was:
Built almost twice as fast with fewer people.
Written in 33% fewer lines of code.
Constructed with 40% fewer files."
I don’t take issue with using JS in the backend, particularly not on performance grounds (I work on a bunch of Rails apps, it’s not fast, but it’s fine for a lot of problems).
Not a big fan of that article though. I wouldn’t draw anything from it other than “2013 Paypal had issues” (curious how things look there now). Charles Nutter summed it up well.
I just don’t know how much I trust that one datapoint. So the java app was the “backup”. Something tells me their best and brightest weren’t working on the “backup plan”. Also wrt to “Built almost twice as fast with fewer people.” my old CTO used to have a great saying. He said: “I think 10 people can get almost twice as much done as 1”.