Pianory Ties Course Progress to Step Evidence Rather Than Session Endings

The developer of Pianory, a browser-based piano practice app, argues that a finished playback session only shows that playback ended, not that a course step was completed. Progress is instead governed by each step's evidence requirements, such as self-report ratings, quiz scores, or measured observations checked against configured rules. The app's logic also verifies that an attempt matches the active enrollment, course version, and current step before advancing, and partial results keep the learner on the same step. Progress snapshots and immutable attempt records are saved together in one IndexedDB transaction, with replays of identical evidence treated as no-ops and conflicting reuse flagged. The author notes the article describes source code and spec behavior only, and that the test suite was not run for it.