I have a fully-built mobile app that now needs to move its backend to Firebase. The job is to refactor the existing code so the app talks seamlessly to Firebase for three main areas: Firestore (our primary database), real-time data updates, and Cloud Storage for screenshots that users upload inside the app. The app has three roles—Admin, Captain, and Player. Admins and Captains must be able to read and write; Players will read only. I will supply the current source code and a brief walkthrough of the existing data flows so you can wire everything up correctly. What I need from you • Re-code the data layer to use Firebase SDK calls instead of the current solution. • Design a Firestore schema that covers game data plus screenshot references, then create the matching indexes. • Write Security Rules for both Firestore and Cloud Storage that enforce the role-based access above. • Implement Storage Rules that keep screenshots private to the proper team and prevent overwrites. • Deliver clear setup notes so I can replicate the environment in dev, staging, and production. Acceptance I will consider the task complete when: 1. The app compiles against Firebase, syncs data in real time, and uploads/serves screenshots from Cloud Storage. 2. Attempted actions outside a user’s permission set are blocked by Firebase rules (I will run tests with Admin, Captain, and Player accounts). 3. You provide the updated project files plus a concise README explaining any environment variables, service accounts, and deployment steps. If you have recent experience with Firebase migration—especially Firestore rules and Cloud Storage security—this should be a straightforward assignment.