They started a rewrite-from-scratch of all the apps, including mobile, using a custom in-house server-driven UI framework with a Kotlin DSL backing it, without so much as doing a proof of concept to find the tricky parts first. And by “started” I mean “committed to it” before anyone had so much as written a line of code to spike it out. Which, YMMV, but to me that seemed then, and still seems now, just wild.