I need a working proof-of-concept that lets anyone post a short note and immediately see every note that has been stored. The stack is fixed: ReactJS on the front end, Flask on the back end, and Firebase (Cloud Firestore or Realtime Database—whichever you prefer) for storage. Front end • A single-page React app with a clean, modern feel. One input field and a “Send” button are plenty, followed by a live list of all messages returned from the API. • Fetch the list after every successful post so the page always shows the latest data without a manual refresh. Back end • Lightweight Flask service exposing two routes: POST /messages to save a note and GET /messages to return everything. • The service should call Firebase through its Python SDK; no ORM layer is needed beyond that. Deliverables • Complete, well-commented source code for React, Flask, and any helper scripts. • A concise README that walks me through setup: Firebase project creation, environment variables, local dev commands (npm start / flask run), and how to push to production if desired. • Quick sanity check that the whole stack runs on a fresh machine in under five minutes. Keep the solution lean; no auth, no extra features—just the essentials done cleanly and within my USD 40 budget.