Common errors.
PUTTING EVERYTHING IN A GLOBAL STORE
Which makes the application difficult to reason about, and re-renders broadly.
DUPLICATING THE SAME DATA IN SEVERAL PLACES
The copies diverge, and nobody knows which is correct.
STORING DERIVED VALUES
Compute them instead.
TREATING SERVER DATA AS OWNED STATE
It is a cache, and needs invalidation.
NOT PUTTING FILTERS AND SEARCH IN THE ADDRESS
Users cannot share or return to what they were looking at.
SELECTING TOO BROADLY
Components re-rendering when unrelated state changes.
USING CONTEXT FOR FREQUENTLY CHANGING VALUES
Everything consuming it re-renders on every change.
SHARED STORES ON THE SERVER
Leaking data between users, which is a serious fault.
NO CONVENTION FOR WHERE STATE LIVES
Producing state scattered unpredictably.
WHAT PREVENTS MOST OF THESE
One source of truth for each piece of data, and keeping state as local as possible.
WHAT TO ASK OF ANY STATE
Who owns this, and who needs it?
