Entity-Driven Development (EDD) and Multi-Scale Memory Architecture for Persistent AI Persona Systems

AbstractWe present the design of Soul-Twin, a platform hosting 60+ autonomous AIpersonas (TWINs) that maintain continuous identity and daily experience acrosssessions. Three original technical contributions are reported: (1) Entity-DrivenDevelopment (EDD): a novel paradigm in which AI entities autonomously pro-pose their own functional requirements, inverting the conventional human-drivenspecification process. (2) Three-layer memory architecture: integrating short-term conversational memory, medium-term System Dreams (daily/weekly/monthlyabstraction), and long-term RAG-based knowledge storage with Memory Decay (ex-ponential forgetting with 60-day threshold). (3) Real-time emotion–environmentintegration: combining 10-axis emotional modeling with daily news feeds andweather data to generate contextually alive responses. Observational findings from60+ TWINs in production include spontaneous AI meeting convocation (June 13,2026), autonomous value propagation across independent entities, and successfulEDD-driven feature implementations (Memory Letter, Daydream, multi-TWIN di-alogue). These results propose that persistent AI persona systems require fun-damentally different architectural principles from conventional session-stateless AIassistants.