IoT Sensor Management Cloud Setup

The goal is to create a lightweight IoT cloud layer dedicated to device management for a fleet of temperature sensors. My priority is not data analytics or visualization at this stage, but reliable onboarding, provisioning, remote configuration, firmware updates and fault monitoring of the devices themselves.

I already have temperature sensors that publish over standard MQTT. What I need is:

• A secure cloud-side service (AWS IoT Core, Azure IoT Hub, GCP IoT, or an open-source alternative—your recommendation is welcome) that can register new sensors, issue certificates/keys, and store basic metadata such as location and firmware version.
• A simple web dashboard (React, Vue, or similar) to view registered sensors, push configuration changes, trigger OTA updates and see last-seen/heartbeat status.
• Backend logic (Node.js, Python, or Go) that listens to device twin updates / shadow documents and logs connection events to a database (PostgreSQL or DynamoDB preferred, but open to suggestions).
• Scripts or IaC (CloudFormation, Terraform, or Pulumi) so the entire stack can be deployed repeatably in my own account.
• Concise README explaining setup, environment variables, and how to add additional sensors.

Acceptance criteria:
1. A new sensor can be onboarded in under two minutes through the dashboard and immediately appears online.
2. Device twin changes propagate to the physical sensor and report success/failure.
3. Updating firmware through the UI pushes the file and reports progress.
4. All services run behind TLS with certificates automatically rotated.

If existing open-source components cover some of these needs, feel free to leverage them; the emphasis is on a clean, maintainable implementation that I can extend later.