<i>EDIT: I changed that paragraph; thanks for pointing out it no longer fit with the rest of the post.</i><p><i>Original comment</i>:<p>The weakness of typing in the switch blocks. I&#x27;ll alter that sentence a bit; it&#x27;s a leftover from an earlier version of that article where I was going to focus very narrowly on how uMsg&#x2F;wParam&#x2F;lParam, like the way actions are usually done in Flux apps, are decoupled to the point where it&#x27;s very easy to make typing errors. Then I described why I thought they were similar to begin with, and then axed most of the original post when the entire thing switched to showing how Flux is an old pattern we&#x27;ve done before. I&#x27;ll see if I can tweak that sentence in a way that keeps the flow going.