Previously I reported on long Elm compilation times and that being related to large .elmi files. In an Elm discourse thread Warry links to their new package elm-stuff for decoding .elmi and .elmo files. So if you are having Elm compilation time woes, you could potentially use this, to inspect the large .elmi files and see exactly what may be causing them to be so large. This may guide you to the best large record files to make opaque to reduce your application’s compilation time.