I architected a production-grade RBAC/permission system and shipped 8+ core modules for a solar financing platform using Next.js 15 and TypeScript. Built granular access control with route guards, HOCs, and protected modules to support secure multi-admin collaboration across users, loans, marketplace, transactions, and team management. Integrated 11+ REST services with SWR (optimistic updates, retries, data mappers) and cut API calls by ~40% through intelligent caching, delivering features like loan lifecycle management, marketplace filtering, wallet/transaction monitoring, user verification, and admin/team setup with full TypeScript safety and responsive UI.