Screen states: empty, loading, error — and the ones people forget until a bug arrives
Screens get designed for the happy path, but the user sees loading, emptiness or an error first. A first-person walkthrough: the empty screen that looks like a stuck loader; why 'nothing here yet' and 'nothing found' are different empties; why an error must not look like emptiness; offline, partial load, stale data, errors on load-more; accessibility of empty and error states, plus a compact checklist.