I've also built several production systems and it has nothing but nightmare. Stack traces are meaningless and there were so many issues with things like ISO Time Zones, HTTP requests (why isn't there a solid http request library? its a mess), Docker problems with compilation, start times were atrocious and still are I think, package management is insane, setting up an internal julia repository is a total nightmare - just go on SO and search for it.

I've lived through this.