I’m building Challenge, a reverse marketplace that flips the usual search model on its head. Here, customers describe what they need and service providers race to win the work with the most attractive offer. We cover every kind of service—professional, home-based, and personal—so the platform has to flexibly handle everything from a fitness lesson to a complex legal consultation. The user journey is intentionally conversational: requests are created and negotiated through a real-time chat interface rather than long forms or document uploads. Suppliers receive the brief, submit itemised proposals inside the same thread, and the customer can accept, decline, or keep negotiating. To launch an MVP I need a full-stack solution that includes: • Customer & supplier onboarding with role-based dashboards • Secure, real-time chat (WebSocket or similar) supporting text, attachments, and quoted offers • Matching logic to route each request to relevant suppliers and track bid status • Offer management—price, scope, validity timer, revisions, and acceptance flow • Payment and escrow integration (Stripe or comparable) • Ratings/reviews once the service is completed • Admin panel for user moderation, dispute resolution, and analytics • Responsive web UI; a modular API so a mobile app can follow quickly Acceptance criteria 1. A customer can post a service request, receive at least one supplier offer in-thread, and accept it end-to-end with payment captured in sandbox mode. 2. A supplier can register, verify identity, receive matching requests, and send a structured proposal containing price, timeline, and notes. 3. All chat messages and offer updates appear in real time without page refresh. 4. Admin can suspend any user and refund or release escrow from the dashboard. Tech stack is flexible, but modern frameworks (e.g., React/Next, Node/Nest, Django, or Laravel) with a Postgres or Mongo backend and socket-based messaging are preferred. Quality, clean code and clear documentation are more important than specific languages. Please outline which stack you’d use, any similar marketplaces you’ve built, and your estimated timeline to reach a production-ready MVP.