plain javascript? no strongly typed language compiled to javascript?
Devs have a track record that speaks volumes, but I must say having multiple components in different languages, nodejs which is a nightmare to administer, plain javascript which doesn’t help for maintenance of large code bases, mongodb (dated article, but not reassuring: http://hackingdistributed.com/2014/04/06/another-one-bites-the-dust-flexcoin/) and a full rewrite wrapped in secrecy makes it look really scary as it is usually a recipe for disaster.
Let’s hope my fears will be laughed at when Catapult launches