7How do you model one-to-many and many-to-many relations in Room, and why does such a query need @Transaction?Medium
9A Room query that was instant at a thousand rows takes half a second at a hundred thousand. How do you find and fix it?Hard
10An insert of a row that already exists either silently does nothing or wipes its children. What do the OnConflictStrategy options actually do?Medium
11The user wants an exported PDF saved where their file manager can find it. How do you write it without WRITE_EXTERNAL_STORAGE?Medium
12The user logs out. What exactly has to be cleared, and what breaks if you only clear the token?Easy
13A teammate replaced every apply() with commit() after a setting went missing on a crash — what does each one actually do?Easy
14You insert a row and the list only shows it after leaving the screen and coming back — what is wrong with the DAO?Easy
15At launch the theme flashes the default and only then switches to the user's choice — how should a DataStore-backed setting be read?Medium
16A JSON file the app writes itself sometimes comes back truncated, and sometimes it is gone entirely. Where should it live and how should it be written?Medium
17After an update users crash on launch with "Room cannot verify the data integrity" — what happened, and what do you ship next?Medium
18During a sync your list Flow emits hundreds of times and the screen flickers, though only ten rows really changed — why, and what do you do?Medium
19A repository method that writes inside db.withTransaction hangs forever — no crash, no exception, the coroutine never resumes. Where do you look?Hard
20A user restores your app on a new phone and it crash-loops on launch while decrypting its own preferences — what went wrong?Hard