I am looking for an experienced mobile app developer (Android + iOS) with serverside who can customize Telegram’s open-source code and add new modules on top of it. The app will function like Telegram but will include additional features such as private cloud storage, events listing, nearby user discovery, media compression, and secure account migration. Only developers who have previously modified Telegram source code or have strong experience in secure messaging apps should apply. FEATURES REQUIRED 1. User Account & Security App-level PIN lock to open the app. Login only through phone number (Telegram-style). When user logs in on a new phone, old device should automatically log out. SIM verification required for login (similar to original Telegram). 2. Private Cloud Storage (User-Owned) A separate “Private Cloud Drive” inside the app where users can: Upload media / files Store deleted media from chats with deferent folder Restore files when switching phones Share files from: Phone storage Cloud storage 3. Media Management Custom media compression algorithms for: Images (WebP) Videos (H.265 / VP9) Audio (Opus) Ability to save files directly to cloud or local device Fast preview + download system 4. Events Module (City-Based) A new tab in the app: Shows upcoming events in user’s city Events can be listed by admin through backend dashboard Users can view, join, and save events Location permission required (user-controlled) 5. Nearby Users Feature Show nearby users (distance-based) Only works if user enables location sharing Toggle ON/OFF anytime GPS coordinates stored securely in database 6. Admin Dashboard (Web-Based) Admin should be able to manage: Users (block / enable) Events (add / edit / delete) Cloud storage usage User activity logs (visible functions only, no interception of private messages) NOTE: No hidden surveillance features. All data access must be aligned with app-store policies and user-consent. 7. Database & Backend Store user data, locations (when allowed), events, cloud files Separate storage bucket for deleted-media backup Encrypted storage Scalable backend (Node.js / Go / Python preferred) PostgreSQL or MongoDB for DB S3-compatible storage for media 8. App Restoration on New Phone When user changes phone: Cloud data + chat metadata should restore Old device should be logged out automatically Verification by SMS/OTP DELIVERABLES Fully working Android & iOS apps Source code (mobile + backend + admin dashboard) Deployment documentation Architecture document + database schema Cloud setup (AWS / DigitalOcean / GCP) 3-month bug support TECH STACK (Preferred) Mobile: Flutter / React Native / Native (Kotlin + Swift) Backend: Node.js / Go / Python Database: PostgreSQL / MongoDB Storage: S3 compatible Admin Panel: React / Vue + REST API DEVELOPER REQUIREMENTS Experience modifying Telegram source code Strong knowledge of encryption & secure communication Experience with large-scale backend APIs Should deliver a clean, stable, documented build