Interesting to see Apple starting to move into the web app product space (aside from iCloud, of course). Must say though that performance feels a bit sluggish (esp. hover states) on a Macbook Pro (tested in Firefox, Chrome and Safari).
Not surprising as they are using Ember (one of the slowest front end frameworks), Moment (super heavy date library), and they don't even minify their code...
As you can see Ember 3.11.1 doesn't fare too well in either performance, startup metrics, or memory consumption. Glimmer does a bit better but that not much.
Results of a Lighthouse audit (London): https://www.dropbox.com/s/jaf3gmgo0tpanba/Screenshot%202019-...