The summary.
MOST APPLICATIONS HAVE FAR LESS SHARED STATE THAN ASSUMED
Most of what ends up in a global store is server data or address state.
Ask what genuinely needs sharing, and how often it changes, before adding a library.
SERVER DATA IS A CACHE, NOT STATE YOU OWN
Use a library built for it: caching, deduplication, background refetching, invalidation after mutations.
That removes the majority of the code people write around fetching.
PUT FILTERS, SEARCH AND PAGINATION IN THE ADDRESS
Users expect to share a link to what they are looking at.
ONE SOURCE OF TRUTH FOR EACH PIECE OF DATA
Never duplicate it, and never store derived values — compute them.
CONTEXT AND PROVIDE FACILITIES ARE FOR VALUES THAT CHANGE RARELY
Frequently changing values re-render everything consuming them.
A SHARED STORE ON A SERVER LEAKS DATA BETWEEN USERS
Check how any library handles server rendering before using it there.
