i worked at a big company ($10B+) that was heavy on scala and akka. we had tons of bugs across almost every team trying to figure out which application.conf was setting something or getting overwritten from somewhere else. we had many unnecessary configs to force something we couldn’t figure out. we had maybe 2 people who actually understood it and could debug it. what a horrible system. no one ever walked away from akka and said i enjoy the decisions they made to configure it