Disclosure: I build VibeLing , a vocabulary app. This post is about the scheduler inside it — what it does, what we deliberately didn't build, and the thing that broke once real people started using it. Every spaced repetition app has one function at its core: given a word and everything that h...
Source: [Dev.to](https://dev.to/vitaly_pavlenko_71b14d120/spaced-repetition-under-the-hood-how-we-decide-when-to-show-a-word-again-2g5b)