SmartMornitoring System Development

Title: Custom IoT Backend + Flutter Mobile App for Smart Monitoring System
Description:
We're building FloraPulse, a commercial smart plant watering system using ESP32 microcontrollers with soil moisture/temperature sensors across up to 6 pots, plus pump control.
Our ESP32 firmware is being handled in-house and will communicate via MQTT (topics and payload structure will be provided/finalized together). We need the backend and mobile app built to work with this setup.
What we need:
1. Backend Server

Node.js or Python (your choice) + database (PostgreSQL/MongoDB)
MQTT broker integration (self-hosted Mosquitto or managed service — your recommendation)
REST API for mobile app: read sensor data, send control commands, manage devices
User authentication (signup/login, multi-tenant — each customer manages their own device)
Push notification triggers (low water, low moisture, device offline, watering complete)

2. Flutter Mobile App (iOS + Android)

Custom UI matching our provided design (attached) — branded dashboard, sliders for pump speed/watering duration, start watering button, device status, water reservoir level
Sensor monitoring screen — soil moisture & temperature for 6 pots, color-coded status
Push notifications (Firebase Cloud Messaging)
User login/device pairing flow

3. Deployment

Backend deployed to cloud (AWS/DigitalOcean/Render — your recommendation)
App builds prepared for App Store & Play Store submission (we'll provide developer accounts)

Attached: Reference UI design, MQTT topic/payload spec (to be shared)
Requirements:

Backend development (Node.js/Python) + database design + MQTT experience
Flutter development (published apps preferred)
Familiarity with Firebase push notifications

Please share:

Similar projects you've completed (IoT backend + mobile app)
Estimated timeline
Fixed cost quotation
Your recommended tech stack (backend framework, hosting, MQTT broker)

Budget: Open to discussion based on your proposed timeline and stack.