{"id":"write-read-cost-allocation-is-per-use-case","text":"The codebase demonstrates both strategies for derived state maintenance — eagerly rebuilding on every write (autocomplete caches, leaderboard reindexing) and lazily deferring computation to reads (time decay, expiration, balance derivation) — showing that write-vs-read cost allocation is a deliberate per-use-case design choice, not a single architectural pattern.","truth_value":"IN","source":"","source_url":"","source_hash":"","justifications":[{"type":"SL","antecedents":["eager-rebuild-trades-write-cost-for-derived-consistency","lazy-read-time-evaluation-trades-write-simplicity-for-read-cost"],"outlist":[],"label":"These two depth-1 conclusions represent opposite strategies for the same problem (when to compute derived state), revealing a spectrum rather than a convention"}],"dependents":["metrics-instantiates-write-read-cost-pattern","write-cost-allocation-matches-access-pattern"],"metadata":{"last_reviewed":"2026-06-06T06:26:57","review_result":"pass"},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"write-read-cost-allocation-is-per-use-case","truth_value":"IN","reason":"SL justification valid","antecedents":["eager-rebuild-trades-write-cost-for-derived-consistency","lazy-read-time-evaluation-trades-write-simplicity-for-read-cost"],"label":"These two depth-1 conclusions represent opposite strategies for the same problem (when to compute derived state), revealing a spectrum rather than a convention"},{"node":"eager-rebuild-trades-write-cost-for-derived-consistency","truth_value":"IN","reason":"SL justification valid","antecedents":["autocomplete-cache-consistency","leaderboard-update-by-remove-reinsert"],"label":"autocomplete rebuilds top_k_cache for all ancestor nodes on every trie mutation; leaderboard removes and reinserts entries on score update — both choose O(mutation) rebuild over eventual consistency of derived structures"},{"node":"autocomplete-cache-consistency","truth_value":"IN","reason":"premise"},{"node":"leaderboard-update-by-remove-reinsert","truth_value":"IN","reason":"premise"},{"node":"lazy-read-time-evaluation-trades-write-simplicity-for-read-cost","truth_value":"IN","reason":"SL justification valid","antecedents":["autocomplete-decay-is-read-time","url-shortener-expiration-lazy","payment-balance-never-cached"],"label":"Three independent systems chose lazy evaluation, suggesting write-simplicity is the dominant concern in pedagogical implementations"},{"node":"autocomplete-decay-is-read-time","truth_value":"IN","reason":"premise"},{"node":"url-shortener-expiration-lazy","truth_value":"IN","reason":"premise"},{"node":"payment-balance-never-cached","truth_value":"IN","reason":"premise"}]}}