30Build an in-memory database: set/get/delete → field operations and prefix scan → TTL → backup and restore at timestamps▼hardOpenAIScalexAI2 replies◆ premiumThe OpenAI FDE signature question, reported near-verbatim for two years: four levels in ~60 minutes, where L4 silently breaks every naive L3 implementation. The lazy-expiry design that survives all four levels, with the pacing plan.Open full answer →
31Build an in-memory SQL-like table: schema and select → WHERE → combined && / || clauses → ORDER BY▼hardOpenAI1 replies◆ premiumThe other OpenAI signature build, reported in four parts for two years. Part C silently punishes anyone who hardcoded single-condition filtering in part B; here's the predicate-compiler design that absorbs all four parts.Open full answer →