IOT Middle-ware Architecture Development -- 2

I am Android Application Engineer and also Have Embedded Knowledge. I want to make ESP32 Based Products Operating with Android Apps. I want Full IOT Server Setup for Selecting right middle-ware architectural and Scalable DB.

My Role: Developing ESP32 Hardware + Android Application Development.

Your Role: Developing IOT platform for multiple devices which Include
- IOT Server Setup for Selecting right middle-ware architectural
- Setting up Cloud server( Either Personal VPS or AWS/Google/Azure)
- Data processing pipelines customized to process data received from different type of devices
- Scalable DB Setup
- REST API development for using data on web or mobile apps

Must have sound Knowledge of MQTT, AMQP, Google IOT Core, AWS Iot Core, Azsure etc.

Expectation:
- Reliable Technology
- Low Cost
- Secure
- Scalable