The asset compilation scripts edxapp-update-assets-lms and edxapp-update-assets-cms duplicate a lot of work between them. Running webpack twice also seems to cause an intermittent error where the second build results in a different bundle hash than the first. It is possible to run "paver update_assets" without specifying "lms" or "cms", in which case it just compiles it all at the same time. This removes the duplicate invocations of webpack and should speed the build overall.