10 Devices and 10,000 Devices Are Completely Different Problems

You can manually configure 10 devices.

You probably don't want to manually configure 10,000.

At that point, you need proper device management.

You want to know:

Which devices exist?
Which are online?
Which firmware version are they running?
Which haven't communicated recently?
Which need an update?
Which are failing?

This is where IoT starts feeling less like a small programming project and more like infrastructure engineering.

You need provisioning.

You need monitoring.

You need automated updates.

You need authentication.

You need a way to retire devices.

The software isn't just managing data anymore.

It's managing a large population of physical computers.

That's a pretty interesting engineering problem.