Project Overview We are looking for a senior Firebase developer to implement Firebase as a CRM layer integrated with our existing backend infrastructure hosted on Hostinger. The application backend is already live and managed on a dedicated server. Firebase will not replace the backend. Instead, it will function as a structured CRM system to manage users, leads, activity tracking, notifications, segmentation, and engagement workflows. The objective is to build a secure, scalable Firebase environment that synchronises with our current server and enables operational visibility, automation, and structured data management. Current Infrastructure: Backend hosted on Hostinger (existing APIs operational) Mobile application connected to existing server Firebase to be implemented as CRM and engagement infrastructure Scope of Work: Firebase project setup and environment configuration; Firestore CRM data modelling including users, leads, activity logs, tags and segmentation; Secure API integration with existing Hostinger backend; Webhooks or scheduled data synchronisation; Cloud Functions for automation and workflow triggers; Role-based access control and security rules implementation; Firebase Cloud Messaging setup for segmented notifications; Analytics event tracking and reporting structure; App Check and server-to-server authentication; Full technical documentation and handover session.