Architected and developed an end-to-end rental management ERP platform focused on simplifying and centralizing day-to-day rental operations. Designed reusable customer and instrument management workflows with searchable selection, dynamic rental item allocation, quantity and rate configuration, rental date and time tracking, advance payment management, payment method handling, notes, and complete rental lifecycle tracking. Implemented structured rental status workflows including Pending Payment, Running Payment, Cleared, and Uncleared states with server-driven search and status filtering. Built efficient cursor-based pagination with MongoDB-backed queries and infinite scrolling to handle large rental datasets without relying on traditional page-based pagination. Implemented optimized data-fetching and caching workflows using TanStack Query with query invalidation for reliable synchronization between rental, customer, and instrument operations. Developed production-grade forms using React Hook Form and Zod validation, including reusable add/edit workflows with backend-driven prefilled data, conditional payment-method validation, dynamic rental instrument rows, duplicate-instrument prevention, quantity and rate calculations, and responsive user interactions. Integrated Axios-based API communication with a structured Express.js backend and MongoDB database architecture. Designed responsive, component-driven interfaces using Tailwind CSS with a focus on usability, maintainability, and consistent UX across operational workflows. The platform provides a centralized system for managing customers, rental records, instruments, payments, rental history, and business operations while significantly reducing manual record-keeping and improving operational visibility.