> Why do they keep redoing the exercise system? It seemed that they are changing for the sake of changing. Most of the recent changes have been focused on two

> Why do they keep redoing the exercise system? It seemed that they are changing for the sake of changing. Most of the recent changes have been focused on two axes, very tightly related: 1. The old exercise system did not work sanely on mobile. Supporting mobile required both front- and backend changes. 2. As part of that, we wanted to extend the kinds of things we could do in exercises so that they'd be usable for more than just the simple math problems they've been focused on until now. We all know there were some minor regressions in the process of getting there, but we're basically done with the tear-it-down-and-rebuild-it part of the process, so the churn should be a lot saner now.