The current watch mode for webpack is fairly good at caching load results and general workload between file changes as long as you keep the same webpack process running. The initial build for some projects, on the other hand, can be on the order of more than a minute. This can make the build process very slow if for some reason you need to stop your watcher, or node crashes, or you simply want to restart your connect server with different flags.
It would be nice if webpack were able to persist compilation information between invocations of the node process to the filesystem and reload that cache later — so ideally, performance between different
$ webpack calls would be close to how long it takes to
--watch to recompile when it detects a change.