It sounds like you have a lot of operation issues due to the technologies that you used. I mean, at least you aren't doing your backend in node, but running an actor system on top of an actor system is going to be brutal to properly analyze once you actually have scale.
What sort of process do you have for picking trendy technologies vs tested ones, and how much do you talk to people who have built large scale systems before implementing things like scala?
What sort of process do you have for picking trendy technologies vs tested ones, and how much do you talk to people who have built large scale systems before implementing things like scala?