SIGANTENG REST API Developed a REST API for the SIGANTENG application, designed to handle user registration, water reporting, payments, and customer complaints for PDAM Tirta Benteng Tangerang. Tech Stack Backend: NestJS (TypeScript) Database: PostgreSQL, MongoDB Caching & Queue: Redis Authentication: JWT Third-Party Integration: WhatsApp API, Payment Gateway, Firebase Key Features : ✅ Customer Registration: API for registering new customers and integrating existing customers with the application. ✅ Automated Notifications: Integrated with WhatsApp API and Firebase Cloud Messaging (FCM) for automated notifications. ✅ Online Payment Integration: Integrated with a Payment Gateway to enable secure online payments.