Why Sub-50ms API Responses Matter for Checkout Flows — and What That Really Takes

https://zulu-wiki.win/index.php/One_Ruleset_for_POS_App_CRM_Marketplace_Channels:_Why_Unified_Promotion_Logic_Wins

Which API performance and integration questions actually decide whether a checkout converts or crashes? If you build or buy payment and checkout systems, you face a handful of questions that determine revenue, fraud risk, and engineering