| Layer | Technology | |-------|-------------| | Frontend | React (web) / React Native (mobile) / Electron (desktop) | | Backend | Node.js + Express | | Database | PostgreSQL (relational data) + Redis (caching) + S3 (images/videos) | | Search | Elasticsearch | | Authentication | OAuth (Google, Discord) + optional local account | | API | REST + GraphQL for complex queries | | 3D models | Three.js (web) / RealityKit (iOS) / OpenGL (desktop) |