Full-Stack Developer – Build Social Network MVP (Flutter/React/Node.js

Job Title: Full-Stack Developer – Build Social Network MVP (Flutter/React/Node.js) Job Type: Fixed-price Budget: $30,000 (Guideline – negotiable based on proposal quality) Project Length: 3 to 6 months Experience Level: Expert About the Project We are building ConnectSphere – an ambitious African technology platform that combines social networking, education, business collaboration, and marketplace services into a single ecosystem. This is a well-funded startup with a clear vision and phased development roadmap. Phase 1 is the MVP: a fully functional social networking platform with messaging and voice/video calling. We are looking for an expert full-stack developer (or a small team) to take this from concept to launch. Who We Are: • Company: ConnectSphere Technologies Ltd. • Location: Lusaka, Zambia • Industry: Technology (Social Networking, EdTech, Business Collaboration) • Target Market: Africa initially, then global • Hosting Partner: HostGush – www.HostGush.com (our own hosting infrastructure – VPS and dedicated servers), actually you must factor hosting in your price. Why We Are Hiring an Expert This is not a simple CRUD app. We are building real-time features (WebSockets) and peer-to-peer video calls (WebRTC) that must work reliably on diverse networks (3G, 4G, WiFi) and low-end Android devices common in Africa. We need a developer who has already built a messaging or calling app before. We cannot afford to have someone "learn on the job." Your expertise will save us time, money, and headaches. Key Features for Phase 1 MVP Module Features User System Registration (email/phone + SMS OTP verification), login, profile creation (photo, bio, cover image), password reset Social Feed Text/image/video posts, like/comment/share, follow/unfollow, search users by name/location Messaging One-to-one chat, text/images/videos/voice notes/files, GIFs, stickers, read receipts, message reactions, edit/delete messages Voice & Video Calls HD peer-to-peer voice and video calls (WebRTC) Admin Panel Basic dashboard for user/content moderation Future Phases (to be developed later – opportunity for long-term collaboration): • Student Hub (classrooms, assignments, online classes, academic library) • Business Hub (team chat, task management, Kanban, CRM) • Marketplace (buy/sell, payments, delivery tracking) • AI Assistant, Events, and Communities Technology Stack Requirements Layer Technology Mobile Frontend Flutter (Android & iOS) – MANDATORY Web Frontend React with Redux Backend API Node.js with NestJS Real-time Socket.IO (WebSockets) Main Database PostgreSQL Cache Redis File Storage AWS S3 or Cloudflare R2 Authentication Firebase Authentication or Auth0 Push Notifications Firebase Cloud Messaging (FCM) Video Calls WebRTC with STUN/TURN servers Deliverables Upon completion, you must deliver: 1. Source Code: Complete, well-documented codebase (private Git repository) 2. Mobile Apps: APK (Android) and IPA (iOS) builds for testing 3. Web App: Deployed and functional web application 4. API Documentation: Swagger/OpenAPI documentation 5. Database Scripts: Migration scripts and seed data 6. Deployment Guide: Step-by-step instructions for hosting on a VPS 7. Admin Panel: Basic admin dashboard for user/content moderation Required Skills & Experience Must-Have Skills (Non-Negotiable): • ✅ Flutter – Proven experience building cross-platform mobile apps (Android & iOS) • ✅ React – Web frontend development • ✅ Node.js – Backend API development (NestJS preferred) • ✅ TypeScript – Strong proficiency • ✅ PostgreSQL – Database design and optimization • ✅ Redis – Caching and session management • ✅ WebRTC – Voice and video calling integration • ✅ WebSockets – Real-time messaging (Socket.IO) • ✅ Firebase Authentication or Auth0 • ✅ AWS S3 or Cloudflare R2 – File storage • ✅ Git – Version control Nice-to-Have: • Experience with African mobile money payment gateways (Flutterwave, DPO, Pesapal) • Experience with educational technology (LMS) platforms • Experience deploying on VPS/cloud environments • Experience with microservices architecture Soft Skills: • Strong written and spoken English • Self-motivated and able to work independently • Willing to work with a startup (agile, fast-paced) • Open to long-term freelance collaboration on Phases 2, 3, and 4 (this is a project-based freelance partnership, not a contract-to-hire for permanent employment) Important Note on Upwork Skill Filters: While Upwork's filtering system prioritizes React, Node.js, TypeScript, and Web Development, please note that Flutter is the absolute core of our mobile app. You must have Flutter experience to be considered. Proposals without Flutter portfolio examples will be ignored. Project Timeline (Suggested) Sprint Duration Deliverable Sprint 1 Weeks 1–3 Project setup, database design, user authentication (registration/login/profiles) Sprint 2 Weeks 4–6 Social Feed (posts, like/comment/share, follow/unfollow, search) Sprint 3 Weeks 7–10 Messaging (one-to-one chat, text/images/voice notes/files, read receipts, reactions) Sprint 4 Weeks 11–14 Voice & Video Calls (WebRTC integration) Sprint 5 Weeks 15–18 Admin Panel, Testing, Bug Fixes, Deployment, Documentation Total 3–6 months Production-ready MVP Budget & Payment Milestones Guideline Budget: $30,000 (Fixed Price) How we evaluate proposals: We are not automatically choosing the lowest bid. We are choosing the developer/team who demonstrates the best understanding of the technical complexity (real-time chat, WebRTC video, scalable databases) at a fair price. We value justification over the lowest number. Payment Structure – 5 Milestones: To protect both parties, we will structure payments across clear, verifiable milestones. Payment is released only after we have reviewed and approved each deliverable. Milestone Deliverable Payment (%) Approximate Amount 1 Project setup, database design, user authentication, profile creation 15% $4,500 2 Social Feed (posts, like/comment/share, follow/unfollow, search) 20% $6,000 3 Messaging (one-to-one chat, text/images/voice notes/files, read receipts, reactions) 25% $7,500 4 Voice & Video Calls (WebRTC integration) 25% $7,500 5 Admin Panel, Testing, Bug Fixes, Deployment, Documentation 15% $4,500 TOTAL 100% $30,000 Note: The exact milestone amounts are negotiable. If your proposal is, say, $25,000 or $32,000, we will adjust percentages accordingly. In your proposal, please include: 1. Your fixed-price total for Phase 1. 2. A rough breakdown of hours/cost per major module (e.g., "Auth: X,Feed:X,Feed:Y, Messaging: Z,Calls:Z,Calls:W"). 3. Why you believe your estimate is realistic for this scope. Example of a good justification: "Based on my experience building [similar project], the WebRTC integration will take the most time due to signaling server setup and TURN server configuration. I estimate 80–100 hours for that module alone, which is why my total is $X." Proposals that simply state a single number with no breakdown will be deprioritized. How to Apply Please submit a proposal that includes: 1. Brief introduction – who you are and your experience 2. Portfolio – links to previous projects (especially social/messaging/Flutter apps) 3. Relevant experience – specific examples of similar work 4. Proposed timeline – how you would break down the 3–6 months 5. Detailed cost breakdown – as described in the Budget section above Please include this phrase at the beginning of your proposal: "ConnectSphere MVP" – so I know you've read the full description. Custom Questions You Must Answer To ensure you have the required skills, please answer these questions in your proposal: 1. Flutter Experience: Provide a direct link to a Flutter app you have built (App Store, Google Play, or GitHub). If you don't have Flutter experience, please do not apply. 2. WebRTC Experience: Have you integrated WebRTC for voice/video calls before? If yes, briefly describe the project. If no, explain your approach to learning it (this is a red flag unless you have exceptional justification). 3. Cost Justification: Provide a rough percentage breakdown of how you would allocate the budget across the five core modules (Authentication, Feed, Messaging, Calls, Admin/Deployment). Why Work With Us? • Impact: Build a platform that will connect millions across Africa • Growth: Opportunity for long-term collaboration on future phases (Phases 2, 3, 4) • Autonomy: We trust developers to make architectural decisions • Flexible: Work remotely with flexible hours • Stable: Backed by a serious founder with a hosting business (HostGush.com) • Portfolio: A high-profile project that will look excellent in your portfolio • Fair: Clear milestones, prompt payments, and professional communication We look forward to your detailed proposals!